diff --git a/src/base-object-inl.h b/src/base-object-inl.h
index db0daa1e82f559..e31435af07285a 100644
--- a/src/base-object-inl.h
+++ b/src/base-object-inl.h
@@ -14,6 +14,10 @@ inline BaseObject::BaseObject(Environment* env, v8::Local<v8::Object> handle)
     : handle_(env->isolate(), handle),
       env_(env) {
   CHECK_EQ(false, handle.IsEmpty());
+  // The zero field holds a pointer to the handle. Immediately set it to
+  // nullptr in case it's accessed by the user before construction is complete.
+  if (handle->InternalFieldCount() > 0)
+    handle->SetAlignedPointerInInternalField(0, nullptr);
 }
 
 
diff --git a/src/fs_event_wrap.cc b/src/fs_event_wrap.cc
index 9d96cd51a24cee..7d1ff18da7449f 100644
--- a/src/fs_event_wrap.cc
+++ b/src/fs_event_wrap.cc
@@ -84,8 +84,8 @@ void FSEventWrap::New(const FunctionCallbackInfo<Value>& args) {
 void FSEventWrap::Start(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  FSEventWrap* wrap = Unwrap<FSEventWrap>(args.Holder());
-  CHECK_EQ(wrap->initialized_, false);
+  FSEventWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   if (args.Length() < 1 || !args[0]->IsString()) {
     return env->ThrowTypeError("filename must be a valid string");
@@ -165,7 +165,8 @@ void FSEventWrap::OnEvent(uv_fs_event_t* handle, const char* filename,
 
 
 void FSEventWrap::Close(const FunctionCallbackInfo<Value>& args) {
-  FSEventWrap* wrap = Unwrap<FSEventWrap>(args.Holder());
+  FSEventWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   if (wrap == nullptr || wrap->initialized_ == false)
     return;
diff --git a/src/handle_wrap.cc b/src/handle_wrap.cc
index 3fc33cbd5bb58f..318300c2540a83 100644
--- a/src/handle_wrap.cc
+++ b/src/handle_wrap.cc
@@ -18,7 +18,8 @@ using v8::Value;
 
 
 void HandleWrap::Ref(const FunctionCallbackInfo<Value>& args) {
-  HandleWrap* wrap = Unwrap<HandleWrap>(args.Holder());
+  HandleWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   if (IsAlive(wrap)) {
     uv_ref(wrap->handle__);
@@ -28,7 +29,8 @@ void HandleWrap::Ref(const FunctionCallbackInfo<Value>& args) {
 
 
 void HandleWrap::Unref(const FunctionCallbackInfo<Value>& args) {
-  HandleWrap* wrap = Unwrap<HandleWrap>(args.Holder());
+  HandleWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   if (IsAlive(wrap)) {
     uv_unref(wrap->handle__);
@@ -40,7 +42,8 @@ void HandleWrap::Unref(const FunctionCallbackInfo<Value>& args) {
 void HandleWrap::Close(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  HandleWrap* wrap = Unwrap<HandleWrap>(args.Holder());
+  HandleWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   // guard against uninitialized handle or double close
   if (!IsAlive(wrap))
diff --git a/src/js_stream.cc b/src/js_stream.cc
index 6ebdb5a3564136..e51c4ae9b35084 100644
--- a/src/js_stream.cc
+++ b/src/js_stream.cc
@@ -135,7 +135,8 @@ static void FreeCallback(char* data, void* hint) {
 
 
 void JSStream::DoAlloc(const FunctionCallbackInfo<Value>& args) {
-  JSStream* wrap = Unwrap<JSStream>(args.Holder());
+  JSStream* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   uv_buf_t buf;
   wrap->OnAlloc(args[0]->Int32Value(), &buf);
@@ -150,7 +151,8 @@ void JSStream::DoAlloc(const FunctionCallbackInfo<Value>& args) {
 
 
 void JSStream::DoRead(const FunctionCallbackInfo<Value>& args) {
-  JSStream* wrap = Unwrap<JSStream>(args.Holder());
+  JSStream* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   CHECK(Buffer::HasInstance(args[1]));
   uv_buf_t buf = uv_buf_init(Buffer::Data(args[1]), Buffer::Length(args[1]));
@@ -159,8 +161,11 @@ void JSStream::DoRead(const FunctionCallbackInfo<Value>& args) {
 
 
 void JSStream::DoAfterWrite(const FunctionCallbackInfo<Value>& args) {
-  JSStream* wrap = Unwrap<JSStream>(args.Holder());
-  WriteWrap* w = Unwrap<WriteWrap>(args[0].As<Object>());
+  JSStream* wrap;
+  CHECK(args[0]->IsObject());
+  WriteWrap* w;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
+  ASSIGN_OR_RETURN_UNWRAP(&w, args[0].As<Object>());
 
   wrap->OnAfterWrite(w);
 }
@@ -168,14 +173,17 @@ void JSStream::DoAfterWrite(const FunctionCallbackInfo<Value>& args) {
 
 template <class Wrap>
 void JSStream::Finish(const FunctionCallbackInfo<Value>& args) {
-  Wrap* w = Unwrap<Wrap>(args[0].As<Object>());
+  Wrap* w;
+  CHECK(args[0]->IsObject());
+  ASSIGN_OR_RETURN_UNWRAP(&w, args[0].As<Object>());
 
   w->Done(args[1]->Int32Value());
 }
 
 
 void JSStream::ReadBuffer(const FunctionCallbackInfo<Value>& args) {
-  JSStream* wrap = Unwrap<JSStream>(args.Holder());
+  JSStream* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   CHECK(Buffer::HasInstance(args[0]));
   char* data = Buffer::Data(args[0]);
@@ -197,7 +205,8 @@ void JSStream::ReadBuffer(const FunctionCallbackInfo<Value>& args) {
 
 
 void JSStream::EmitEOF(const FunctionCallbackInfo<Value>& args) {
-  JSStream* wrap = Unwrap<JSStream>(args.Holder());
+  JSStream* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   wrap->OnRead(UV_EOF, nullptr);
 }
diff --git a/src/node_contextify.cc b/src/node_contextify.cc
index 7404bbba87ec45..d05f8e8f0e6baf 100644
--- a/src/node_contextify.cc
+++ b/src/node_contextify.cc
@@ -340,8 +340,8 @@ class ContextifyContext {
   static void GlobalPropertyGetterCallback(
       Local<Name> property,
       const PropertyCallbackInfo<Value>& args) {
-    ContextifyContext* ctx =
-        Unwrap<ContextifyContext>(args.Data().As<Object>());
+    ContextifyContext* ctx;
+    ASSIGN_OR_RETURN_UNWRAP(&ctx, args.Data().As<Object>());
 
     // Stil initializing
     if (ctx->context_.IsEmpty())
@@ -370,8 +370,8 @@ class ContextifyContext {
       Local<Name> property,
       Local<Value> value,
       const PropertyCallbackInfo<Value>& args) {
-    ContextifyContext* ctx =
-        Unwrap<ContextifyContext>(args.Data().As<Object>());
+    ContextifyContext* ctx;
+    ASSIGN_OR_RETURN_UNWRAP(&ctx, args.Data().As<Object>());
 
     // Stil initializing
     if (ctx->context_.IsEmpty())
@@ -384,8 +384,8 @@ class ContextifyContext {
   static void GlobalPropertyQueryCallback(
       Local<Name> property,
       const PropertyCallbackInfo<Integer>& args) {
-    ContextifyContext* ctx =
-        Unwrap<ContextifyContext>(args.Data().As<Object>());
+    ContextifyContext* ctx;
+    ASSIGN_OR_RETURN_UNWRAP(&ctx, args.Data().As<Object>());
 
     // Stil initializing
     if (ctx->context_.IsEmpty())
@@ -411,8 +411,8 @@ class ContextifyContext {
   static void GlobalPropertyDeleterCallback(
       Local<Name> property,
       const PropertyCallbackInfo<Boolean>& args) {
-    ContextifyContext* ctx =
-        Unwrap<ContextifyContext>(args.Data().As<Object>());
+    ContextifyContext* ctx;
+    ASSIGN_OR_RETURN_UNWRAP(&ctx, args.Data().As<Object>());
 
     // Stil initializing
     if (ctx->context_.IsEmpty())
@@ -427,8 +427,8 @@ class ContextifyContext {
 
   static void GlobalPropertyEnumeratorCallback(
       const PropertyCallbackInfo<Array>& args) {
-    ContextifyContext* ctx =
-        Unwrap<ContextifyContext>(args.Data().As<Object>());
+    ContextifyContext* ctx;
+    ASSIGN_OR_RETURN_UNWRAP(&ctx, args.Data().As<Object>());
 
     // Stil initializing
     if (ctx->context_.IsEmpty())
@@ -690,7 +690,8 @@ class ContextifyScript : public BaseObject {
       return false;
     }
 
-    ContextifyScript* wrapped_script = Unwrap<ContextifyScript>(args.Holder());
+    ContextifyScript* wrapped_script;
+    ASSIGN_OR_RETURN_UNWRAP(&wrapped_script, args.Holder(), false);
     Local<UnboundScript> unbound_script =
         PersistentToLocal(env->isolate(), wrapped_script->script_);
     Local<Script> script = unbound_script->BindToCurrentContext();
diff --git a/src/node_crypto.cc b/src/node_crypto.cc
index 4ae92946c8febb..b3169caa2b884d 100644
--- a/src/node_crypto.cc
+++ b/src/node_crypto.cc
@@ -322,7 +322,8 @@ void SecureContext::New(const FunctionCallbackInfo<Value>& args) {
 
 
 void SecureContext::Init(const FunctionCallbackInfo<Value>& args) {
-  SecureContext* sc = Unwrap<SecureContext>(args.Holder());
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, args.Holder());
   Environment* env = sc->env();
 
   OPENSSL_CONST SSL_METHOD *method = SSLv23_method();
@@ -438,7 +439,8 @@ static X509* LoadX509(Environment* env, Local<Value> v) {
 void SecureContext::SetKey(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  SecureContext* sc = Unwrap<SecureContext>(args.Holder());
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, args.Holder());
 
   unsigned int len = args.Length();
   if (len != 1 && len != 2) {
@@ -638,7 +640,8 @@ int SSL_CTX_use_certificate_chain(SSL_CTX* ctx,
 void SecureContext::SetCert(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  SecureContext* sc = Unwrap<SecureContext>(args.Holder());
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, args.Holder());
 
   if (args.Length() != 1) {
     return env->ThrowTypeError("Bad parameter");
@@ -679,7 +682,8 @@ void SecureContext::AddCACert(const FunctionCallbackInfo<Value>& args) {
   bool newCAStore = false;
   Environment* env = Environment::GetCurrent(args);
 
-  SecureContext* sc = Unwrap<SecureContext>(args.Holder());
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, args.Holder());
   ClearErrorOnReturn clear_error_on_return;
   (void) &clear_error_on_return;  // Silence compiler warning.
 
@@ -710,7 +714,8 @@ void SecureContext::AddCACert(const FunctionCallbackInfo<Value>& args) {
 void SecureContext::AddCRL(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  SecureContext* sc = Unwrap<SecureContext>(args.Holder());
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, args.Holder());
 
   if (args.Length() != 1) {
     return env->ThrowTypeError("Bad parameter");
@@ -741,7 +746,8 @@ void SecureContext::AddCRL(const FunctionCallbackInfo<Value>& args) {
 
 
 void SecureContext::AddRootCerts(const FunctionCallbackInfo<Value>& args) {
-  SecureContext* sc = Unwrap<SecureContext>(args.Holder());
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, args.Holder());
   ClearErrorOnReturn clear_error_on_return;
   (void) &clear_error_on_return;  // Silence compiler warning.
 
@@ -775,7 +781,8 @@ void SecureContext::AddRootCerts(const FunctionCallbackInfo<Value>& args) {
 
 
 void SecureContext::SetCiphers(const FunctionCallbackInfo<Value>& args) {
-  SecureContext* sc = Unwrap<SecureContext>(args.Holder());
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, args.Holder());
   ClearErrorOnReturn clear_error_on_return;
   (void) &clear_error_on_return;  // Silence compiler warning.
 
@@ -789,7 +796,8 @@ void SecureContext::SetCiphers(const FunctionCallbackInfo<Value>& args) {
 
 
 void SecureContext::SetECDHCurve(const FunctionCallbackInfo<Value>& args) {
-  SecureContext* sc = Unwrap<SecureContext>(args.Holder());
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, args.Holder());
   Environment* env = sc->env();
 
   if (args.Length() != 1 || !args[0]->IsString())
@@ -815,7 +823,8 @@ void SecureContext::SetECDHCurve(const FunctionCallbackInfo<Value>& args) {
 
 
 void SecureContext::SetDHParam(const FunctionCallbackInfo<Value>& args) {
-  SecureContext* sc = Unwrap<SecureContext>(args.This());
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, args.This());
   Environment* env = sc->env();
   ClearErrorOnReturn clear_error_on_return;
   (void) &clear_error_on_return;  // Silence compiler warning.
@@ -854,7 +863,8 @@ void SecureContext::SetDHParam(const FunctionCallbackInfo<Value>& args) {
 
 
 void SecureContext::SetOptions(const FunctionCallbackInfo<Value>& args) {
-  SecureContext* sc = Unwrap<SecureContext>(args.Holder());
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, args.Holder());
 
   if (args.Length() != 1 || !args[0]->IntegerValue()) {
     return sc->env()->ThrowTypeError("Bad parameter");
@@ -868,7 +878,8 @@ void SecureContext::SetOptions(const FunctionCallbackInfo<Value>& args) {
 
 void SecureContext::SetSessionIdContext(
     const FunctionCallbackInfo<Value>& args) {
-  SecureContext* sc = Unwrap<SecureContext>(args.Holder());
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, args.Holder());
 
   if (args.Length() != 1 || !args[0]->IsString()) {
     return sc->env()->ThrowTypeError("Bad parameter");
@@ -903,7 +914,8 @@ void SecureContext::SetSessionIdContext(
 
 
 void SecureContext::SetSessionTimeout(const FunctionCallbackInfo<Value>& args) {
-  SecureContext* sc = Unwrap<SecureContext>(args.Holder());
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, args.Holder());
 
   if (args.Length() != 1 || !args[0]->IsInt32()) {
     return sc->env()->ThrowTypeError("Bad parameter");
@@ -915,7 +927,8 @@ void SecureContext::SetSessionTimeout(const FunctionCallbackInfo<Value>& args) {
 
 
 void SecureContext::Close(const FunctionCallbackInfo<Value>& args) {
-  SecureContext* sc = Unwrap<SecureContext>(args.Holder());
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, args.Holder());
   sc->FreeCTXMem();
 }
 
@@ -932,7 +945,8 @@ void SecureContext::LoadPKCS12(const FunctionCallbackInfo<Value>& args) {
   char* pass = nullptr;
   bool ret = false;
 
-  SecureContext* sc = Unwrap<SecureContext>(args.Holder());
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, args.Holder());
   ClearErrorOnReturn clear_error_on_return;
   (void) &clear_error_on_return;  // Silence compiler warning.
 
@@ -1007,7 +1021,8 @@ void SecureContext::LoadPKCS12(const FunctionCallbackInfo<Value>& args) {
 void SecureContext::GetTicketKeys(const FunctionCallbackInfo<Value>& args) {
 #if !defined(OPENSSL_NO_TLSEXT) && defined(SSL_CTX_get_tlsext_ticket_keys)
 
-  SecureContext* wrap = Unwrap<SecureContext>(args.Holder());
+  SecureContext* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   Local<Object> buff = Buffer::New(wrap->env(), 48).ToLocalChecked();
   if (SSL_CTX_get_tlsext_ticket_keys(wrap->ctx_,
@@ -1023,7 +1038,8 @@ void SecureContext::GetTicketKeys(const FunctionCallbackInfo<Value>& args) {
 
 void SecureContext::SetTicketKeys(const FunctionCallbackInfo<Value>& args) {
 #if !defined(OPENSSL_NO_TLSEXT) && defined(SSL_CTX_get_tlsext_ticket_keys)
-  SecureContext* wrap = Unwrap<SecureContext>(args.Holder());
+  SecureContext* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   if (args.Length() < 1 ||
       !Buffer::HasInstance(args[0]) ||
@@ -1043,7 +1059,8 @@ void SecureContext::SetTicketKeys(const FunctionCallbackInfo<Value>& args) {
 
 
 void SecureContext::SetFreeListLength(const FunctionCallbackInfo<Value>& args) {
-  SecureContext* wrap = Unwrap<SecureContext>(args.Holder());
+  SecureContext* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   wrap->ctx_->freelist_max_len = args[0]->Int32Value();
 }
@@ -1051,7 +1068,8 @@ void SecureContext::SetFreeListLength(const FunctionCallbackInfo<Value>& args) {
 
 void SecureContext::EnableTicketKeyCallback(
     const FunctionCallbackInfo<Value>& args) {
-  SecureContext* wrap = Unwrap<SecureContext>(args.Holder());
+  SecureContext* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   SSL_CTX_set_tlsext_ticket_key_cb(wrap->ctx_, TicketKeyCallback);
 }
@@ -1140,15 +1158,17 @@ int SecureContext::TicketKeyCallback(SSL* ssl,
 
 void SecureContext::CtxGetter(Local<String> property,
                               const PropertyCallbackInfo<Value>& info) {
-  SSL_CTX* ctx = Unwrap<SecureContext>(info.This())->ctx_;
-  Local<External> ext = External::New(info.GetIsolate(), ctx);
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, info.This());
+  Local<External> ext = External::New(info.GetIsolate(), sc->ctx_);
   info.GetReturnValue().Set(ext);
 }
 
 
 template <bool primary>
 void SecureContext::GetCertificate(const FunctionCallbackInfo<Value>& args) {
-  SecureContext* wrap = Unwrap<SecureContext>(args.Holder());
+  SecureContext* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
   Environment* env = wrap->env();
   X509* cert;
 
@@ -1522,7 +1542,8 @@ static Local<Object> X509ToObject(Environment* env, X509* cert) {
 template <class Base>
 void SSLWrap<Base>::GetPeerCertificate(
     const FunctionCallbackInfo<Value>& args) {
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
   Environment* env = w->ssl_env();
 
   ClearErrorOnReturn clear_error_on_return;
@@ -1630,7 +1651,8 @@ template <class Base>
 void SSLWrap<Base>::GetSession(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
 
   SSL_SESSION* sess = SSL_get_session(w->ssl_);
   if (sess == nullptr)
@@ -1651,7 +1673,8 @@ template <class Base>
 void SSLWrap<Base>::SetSession(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
 
   if (args.Length() < 1 ||
       (!args[0]->IsString() && !Buffer::HasInstance(args[0]))) {
@@ -1681,7 +1704,8 @@ void SSLWrap<Base>::SetSession(const FunctionCallbackInfo<Value>& args) {
 
 template <class Base>
 void SSLWrap<Base>::LoadSession(const FunctionCallbackInfo<Value>& args) {
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
   Environment* env = w->ssl_env();
 
   if (args.Length() >= 1 && Buffer::HasInstance(args[0])) {
@@ -1712,7 +1736,8 @@ void SSLWrap<Base>::LoadSession(const FunctionCallbackInfo<Value>& args) {
 
 template <class Base>
 void SSLWrap<Base>::IsSessionReused(const FunctionCallbackInfo<Value>& args) {
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
   bool yes = SSL_session_reused(w->ssl_);
   args.GetReturnValue().Set(yes);
 }
@@ -1720,14 +1745,16 @@ void SSLWrap<Base>::IsSessionReused(const FunctionCallbackInfo<Value>& args) {
 
 template <class Base>
 void SSLWrap<Base>::EndParser(const FunctionCallbackInfo<Value>& args) {
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
   w->hello_parser_.End();
 }
 
 
 template <class Base>
 void SSLWrap<Base>::Renegotiate(const FunctionCallbackInfo<Value>& args) {
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
 
   ClearErrorOnReturn clear_error_on_return;
   (void) &clear_error_on_return;  // Silence unused variable warning.
@@ -1739,7 +1766,8 @@ void SSLWrap<Base>::Renegotiate(const FunctionCallbackInfo<Value>& args) {
 
 template <class Base>
 void SSLWrap<Base>::Shutdown(const FunctionCallbackInfo<Value>& args) {
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
 
   int rv = SSL_shutdown(w->ssl_);
   args.GetReturnValue().Set(rv);
@@ -1748,7 +1776,8 @@ void SSLWrap<Base>::Shutdown(const FunctionCallbackInfo<Value>& args) {
 
 template <class Base>
 void SSLWrap<Base>::GetTLSTicket(const FunctionCallbackInfo<Value>& args) {
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
   Environment* env = w->ssl_env();
 
   SSL_SESSION* sess = SSL_get_session(w->ssl_);
@@ -1766,7 +1795,8 @@ void SSLWrap<Base>::GetTLSTicket(const FunctionCallbackInfo<Value>& args) {
 
 template <class Base>
 void SSLWrap<Base>::NewSessionDone(const FunctionCallbackInfo<Value>& args) {
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
   w->new_session_wait_ = false;
   w->NewSessionDoneCb();
 }
@@ -1776,7 +1806,8 @@ template <class Base>
 void SSLWrap<Base>::SetOCSPResponse(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
 #ifdef NODE__HAVE_TLSEXT_STATUS_CB
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
   if (args.Length() < 1 || !Buffer::HasInstance(args[0]))
     return w->env()->ThrowTypeError("Must give a Buffer as first argument");
 
@@ -1789,7 +1820,8 @@ template <class Base>
 void SSLWrap<Base>::RequestOCSP(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
 #ifdef NODE__HAVE_TLSEXT_STATUS_CB
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
 
   SSL_set_tlsext_status_type(w->ssl_, TLSEXT_STATUSTYPE_ocsp);
 #endif  // NODE__HAVE_TLSEXT_STATUS_CB
@@ -1802,7 +1834,8 @@ void SSLWrap<Base>::SetMaxSendFragment(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   CHECK(args.Length() >= 1 && args[0]->IsNumber());
 
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
 
   int rv = SSL_set_max_send_fragment(w->ssl_, args[0]->Int32Value());
   args.GetReturnValue().Set(rv);
@@ -1812,7 +1845,8 @@ void SSLWrap<Base>::SetMaxSendFragment(
 
 template <class Base>
 void SSLWrap<Base>::IsInitFinished(const FunctionCallbackInfo<Value>& args) {
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
   bool yes = SSL_is_init_finished(w->ssl_);
   args.GetReturnValue().Set(yes);
 }
@@ -1820,7 +1854,8 @@ void SSLWrap<Base>::IsInitFinished(const FunctionCallbackInfo<Value>& args) {
 
 template <class Base>
 void SSLWrap<Base>::VerifyError(const FunctionCallbackInfo<Value>& args) {
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
 
   // XXX(bnoordhuis) The UNABLE_TO_GET_ISSUER_CERT error when there is no
   // peer certificate is questionable but it's compatible with what was
@@ -1884,7 +1919,8 @@ void SSLWrap<Base>::VerifyError(const FunctionCallbackInfo<Value>& args) {
 
 template <class Base>
 void SSLWrap<Base>::GetCurrentCipher(const FunctionCallbackInfo<Value>& args) {
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
   Environment* env = w->ssl_env();
 
   OPENSSL_CONST SSL_CIPHER* c = SSL_get_current_cipher(w->ssl_);
@@ -1984,7 +2020,8 @@ int SSLWrap<Base>::SelectNextProtoCallback(SSL* s,
 template <class Base>
 void SSLWrap<Base>::GetNegotiatedProto(
     const FunctionCallbackInfo<Value>& args) {
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
 
   if (w->is_client()) {
     if (w->selected_npn_proto_.IsEmpty() == false) {
@@ -2008,8 +2045,8 @@ void SSLWrap<Base>::GetNegotiatedProto(
 
 template <class Base>
 void SSLWrap<Base>::SetNPNProtocols(const FunctionCallbackInfo<Value>& args) {
-  Base* w = Unwrap<Base>(args.Holder());
-
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
   if (args.Length() < 1 || !Buffer::HasInstance(args[0]))
     return w->env()->ThrowTypeError("Must give a Buffer as first argument");
 
@@ -2128,7 +2165,8 @@ int SSLWrap<Base>::SSLCertCallback(SSL* s, void* arg) {
 
 template <class Base>
 void SSLWrap<Base>::CertCbDone(const FunctionCallbackInfo<Value>& args) {
-  Base* w = Unwrap<Base>(args.Holder());
+  Base* w;
+  ASSIGN_OR_RETURN_UNWRAP(&w, args.Holder());
   Environment* env = w->env();
 
   CHECK(w->is_waiting_cert_cb() && w->cert_cb_running_);
@@ -2142,7 +2180,8 @@ void SSLWrap<Base>::CertCbDone(const FunctionCallbackInfo<Value>& args) {
     goto fire_cb;
 
   if (cons->HasInstance(ctx)) {
-    SecureContext* sc = Unwrap<SecureContext>(ctx.As<Object>());
+    SecureContext* sc;
+    ASSIGN_OR_RETURN_UNWRAP(&sc, ctx.As<Object>());
     w->sni_context_.Reset();
     w->sni_context_.Reset(env->isolate(), ctx);
 
@@ -2193,7 +2232,9 @@ void SSLWrap<Base>::CertCbDone(const FunctionCallbackInfo<Value>& args) {
 template <class Base>
 void SSLWrap<Base>::SSLGetter(Local<String> property,
                               const PropertyCallbackInfo<Value>& info) {
-  SSL* ssl = Unwrap<Base>(info.This())->ssl_;
+  Base* base;
+  ASSIGN_OR_RETURN_UNWRAP(&base, info.This());
+  SSL* ssl = base->ssl_;
   Local<External> ext = External::New(info.GetIsolate(), ssl);
   info.GetReturnValue().Set(ext);
 }
@@ -2546,7 +2587,8 @@ int Connection::SelectSNIContextCallback_(SSL *s, int *ad, void* arg) {
           env->secure_context_constructor_template();
       if (secure_context_constructor_template->HasInstance(ret)) {
         conn->sni_context_.Reset(env->isolate(), ret);
-        SecureContext* sc = Unwrap<SecureContext>(ret.As<Object>());
+        SecureContext* sc;
+        ASSIGN_OR_RETURN_UNWRAP(&sc, ret.As<Object>(), SSL_TLSEXT_ERR_NOACK);
         conn->SetSNIContext(sc);
       } else {
         return SSL_TLSEXT_ERR_NOACK;
@@ -2566,7 +2608,8 @@ void Connection::New(const FunctionCallbackInfo<Value>& args) {
     return;
   }
 
-  SecureContext* sc = Unwrap<SecureContext>(args[0]->ToObject(env->isolate()));
+  SecureContext* sc;
+  ASSIGN_OR_RETURN_UNWRAP(&sc, args[0].As<Object>());
 
   bool is_server = args[1]->BooleanValue();
 
@@ -2654,7 +2697,8 @@ void Connection::SSLInfoCallback(const SSL *ssl_, int where, int ret) {
 
 
 void Connection::EncIn(const FunctionCallbackInfo<Value>& args) {
-  Connection* conn = Unwrap<Connection>(args.Holder());
+  Connection* conn;
+  ASSIGN_OR_RETURN_UNWRAP(&conn, args.Holder());
   Environment* env = conn->env();
 
   if (args.Length() < 3) {
@@ -2703,7 +2747,8 @@ void Connection::EncIn(const FunctionCallbackInfo<Value>& args) {
 
 
 void Connection::ClearOut(const FunctionCallbackInfo<Value>& args) {
-  Connection* conn = Unwrap<Connection>(args.Holder());
+  Connection* conn;
+  ASSIGN_OR_RETURN_UNWRAP(&conn, args.Holder());
   Environment* env = conn->env();
 
   if (args.Length() < 3) {
@@ -2757,21 +2802,24 @@ void Connection::ClearOut(const FunctionCallbackInfo<Value>& args) {
 
 
 void Connection::ClearPending(const FunctionCallbackInfo<Value>& args) {
-  Connection* conn = Unwrap<Connection>(args.Holder());
+  Connection* conn;
+  ASSIGN_OR_RETURN_UNWRAP(&conn, args.Holder());
   int bytes_pending = BIO_pending(conn->bio_read_);
   args.GetReturnValue().Set(bytes_pending);
 }
 
 
 void Connection::EncPending(const FunctionCallbackInfo<Value>& args) {
-  Connection* conn = Unwrap<Connection>(args.Holder());
+  Connection* conn;
+  ASSIGN_OR_RETURN_UNWRAP(&conn, args.Holder());
   int bytes_pending = BIO_pending(conn->bio_write_);
   args.GetReturnValue().Set(bytes_pending);
 }
 
 
 void Connection::EncOut(const FunctionCallbackInfo<Value>& args) {
-  Connection* conn = Unwrap<Connection>(args.Holder());
+  Connection* conn;
+  ASSIGN_OR_RETURN_UNWRAP(&conn, args.Holder());
   Environment* env = conn->env();
 
   if (args.Length() < 3) {
@@ -2801,7 +2849,8 @@ void Connection::EncOut(const FunctionCallbackInfo<Value>& args) {
 
 
 void Connection::ClearIn(const FunctionCallbackInfo<Value>& args) {
-  Connection* conn = Unwrap<Connection>(args.Holder());
+  Connection* conn;
+  ASSIGN_OR_RETURN_UNWRAP(&conn, args.Holder());
   Environment* env = conn->env();
 
   if (args.Length() < 3) {
@@ -2855,7 +2904,8 @@ void Connection::ClearIn(const FunctionCallbackInfo<Value>& args) {
 
 
 void Connection::Start(const FunctionCallbackInfo<Value>& args) {
-  Connection* conn = Unwrap<Connection>(args.Holder());
+  Connection* conn;
+  ASSIGN_OR_RETURN_UNWRAP(&conn, args.Holder());
 
   int rv = 0;
   if (!SSL_is_init_finished(conn->ssl_)) {
@@ -2878,7 +2928,8 @@ void Connection::Start(const FunctionCallbackInfo<Value>& args) {
 
 
 void Connection::Close(const FunctionCallbackInfo<Value>& args) {
-  Connection* conn = Unwrap<Connection>(args.Holder());
+  Connection* conn;
+  ASSIGN_OR_RETURN_UNWRAP(&conn, args.Holder());
 
   if (conn->ssl_ != nullptr) {
     SSL_free(conn->ssl_);
@@ -2889,7 +2940,8 @@ void Connection::Close(const FunctionCallbackInfo<Value>& args) {
 
 #ifdef SSL_CTRL_SET_TLSEXT_SERVERNAME_CB
 void Connection::GetServername(const FunctionCallbackInfo<Value>& args) {
-  Connection* conn = Unwrap<Connection>(args.Holder());
+  Connection* conn;
+  ASSIGN_OR_RETURN_UNWRAP(&conn, args.Holder());
 
   if (conn->is_server() && !conn->servername_.IsEmpty()) {
     args.GetReturnValue().Set(conn->servername_);
@@ -2900,7 +2952,8 @@ void Connection::GetServername(const FunctionCallbackInfo<Value>& args) {
 
 
 void Connection::SetSNICallback(const FunctionCallbackInfo<Value>& args) {
-  Connection* conn = Unwrap<Connection>(args.Holder());
+  Connection* conn;
+  ASSIGN_OR_RETURN_UNWRAP(&conn, args.Holder());
   Environment* env = conn->env();
 
   if (args.Length() < 1 || !args[0]->IsFunction()) {
@@ -2988,7 +3041,8 @@ void CipherBase::Init(const char* cipher_type,
 
 
 void CipherBase::Init(const FunctionCallbackInfo<Value>& args) {
-  CipherBase* cipher = Unwrap<CipherBase>(args.Holder());
+  CipherBase* cipher;
+  ASSIGN_OR_RETURN_UNWRAP(&cipher, args.Holder());
 
   if (args.Length() < 2 ||
       !(args[0]->IsString() && Buffer::HasInstance(args[1]))) {
@@ -3051,7 +3105,8 @@ void CipherBase::InitIv(const char* cipher_type,
 
 
 void CipherBase::InitIv(const FunctionCallbackInfo<Value>& args) {
-  CipherBase* cipher = Unwrap<CipherBase>(args.Holder());
+  CipherBase* cipher;
+  ASSIGN_OR_RETURN_UNWRAP(&cipher, args.Holder());
   Environment* env = cipher->env();
 
   if (args.Length() < 3 || !args[0]->IsString()) {
@@ -3093,7 +3148,8 @@ bool CipherBase::GetAuthTag(char** out, unsigned int* out_len) const {
 
 void CipherBase::GetAuthTag(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
-  CipherBase* cipher = Unwrap<CipherBase>(args.Holder());
+  CipherBase* cipher;
+  ASSIGN_OR_RETURN_UNWRAP(&cipher, args.Holder());
 
   char* out = nullptr;
   unsigned int out_len = 0;
@@ -3125,7 +3181,8 @@ void CipherBase::SetAuthTag(const FunctionCallbackInfo<Value>& args) {
   if (!buf->IsObject() || !Buffer::HasInstance(buf))
     return env->ThrowTypeError("Argument must be a Buffer");
 
-  CipherBase* cipher = Unwrap<CipherBase>(args.Holder());
+  CipherBase* cipher;
+  ASSIGN_OR_RETURN_UNWRAP(&cipher, args.Holder());
 
   if (!cipher->SetAuthTag(Buffer::Data(buf), Buffer::Length(buf)))
     env->ThrowError("Attempting to set auth tag in unsupported state");
@@ -3152,7 +3209,8 @@ void CipherBase::SetAAD(const FunctionCallbackInfo<Value>& args) {
 
   THROW_AND_RETURN_IF_NOT_BUFFER(args[0]);
 
-  CipherBase* cipher = Unwrap<CipherBase>(args.Holder());
+  CipherBase* cipher;
+  ASSIGN_OR_RETURN_UNWRAP(&cipher, args.Holder());
 
   if (!cipher->SetAAD(Buffer::Data(args[0]), Buffer::Length(args[0])))
     env->ThrowError("Attempting to set AAD in unsupported state");
@@ -3189,7 +3247,8 @@ bool CipherBase::Update(const char* data,
 void CipherBase::Update(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  CipherBase* cipher = Unwrap<CipherBase>(args.Holder());
+  CipherBase* cipher;
+  ASSIGN_OR_RETURN_UNWRAP(&cipher, args.Holder());
 
   THROW_AND_RETURN_IF_NOT_STRING_OR_BUFFER(args[0]);
 
@@ -3234,7 +3293,8 @@ bool CipherBase::SetAutoPadding(bool auto_padding) {
 
 
 void CipherBase::SetAutoPadding(const FunctionCallbackInfo<Value>& args) {
-  CipherBase* cipher = Unwrap<CipherBase>(args.Holder());
+  CipherBase* cipher;
+  ASSIGN_OR_RETURN_UNWRAP(&cipher, args.Holder());
   cipher->SetAutoPadding(args.Length() < 1 || args[0]->BooleanValue());
 }
 
@@ -3270,7 +3330,8 @@ bool CipherBase::Final(unsigned char** out, int *out_len) {
 void CipherBase::Final(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  CipherBase* cipher = Unwrap<CipherBase>(args.Holder());
+  CipherBase* cipher;
+  ASSIGN_OR_RETURN_UNWRAP(&cipher, args.Holder());
 
   unsigned char* out_value = nullptr;
   int out_len = -1;
@@ -3341,7 +3402,8 @@ void Hmac::HmacInit(const char* hash_type, const char* key, int key_len) {
 
 
 void Hmac::HmacInit(const FunctionCallbackInfo<Value>& args) {
-  Hmac* hmac = Unwrap<Hmac>(args.Holder());
+  Hmac* hmac;
+  ASSIGN_OR_RETURN_UNWRAP(&hmac, args.Holder());
   Environment* env = hmac->env();
 
   if (args.Length() < 2 || !args[0]->IsString()) {
@@ -3368,7 +3430,8 @@ bool Hmac::HmacUpdate(const char* data, int len) {
 void Hmac::HmacUpdate(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  Hmac* hmac = Unwrap<Hmac>(args.Holder());
+  Hmac* hmac;
+  ASSIGN_OR_RETURN_UNWRAP(&hmac, args.Holder());
 
   THROW_AND_RETURN_IF_NOT_STRING_OR_BUFFER(args[0]);
 
@@ -3405,7 +3468,8 @@ bool Hmac::HmacDigest(unsigned char** md_value, unsigned int* md_len) {
 void Hmac::HmacDigest(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  Hmac* hmac = Unwrap<Hmac>(args.Holder());
+  Hmac* hmac;
+  ASSIGN_OR_RETURN_UNWRAP(&hmac, args.Holder());
 
   enum encoding encoding = BUFFER;
   if (args.Length() >= 1) {
@@ -3486,7 +3550,8 @@ bool Hash::HashUpdate(const char* data, int len) {
 void Hash::HashUpdate(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  Hash* hash = Unwrap<Hash>(args.Holder());
+  Hash* hash;
+  ASSIGN_OR_RETURN_UNWRAP(&hash, args.Holder());
 
   THROW_AND_RETURN_IF_NOT_STRING_OR_BUFFER(args[0]);
 
@@ -3512,7 +3577,8 @@ void Hash::HashUpdate(const FunctionCallbackInfo<Value>& args) {
 void Hash::HashDigest(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  Hash* hash = Unwrap<Hash>(args.Holder());
+  Hash* hash;
+  ASSIGN_OR_RETURN_UNWRAP(&hash, args.Holder());
 
   if (!hash->initialised_) {
     return env->ThrowError("Not initialized");
@@ -3615,7 +3681,8 @@ SignBase::Error Sign::SignInit(const char* sign_type) {
 
 
 void Sign::SignInit(const FunctionCallbackInfo<Value>& args) {
-  Sign* sign = Unwrap<Sign>(args.Holder());
+  Sign* sign;
+  ASSIGN_OR_RETURN_UNWRAP(&sign, args.Holder());
 
   if (args.Length() == 0 || !args[0]->IsString()) {
     return sign->env()->ThrowError("Must give signtype string as argument");
@@ -3638,7 +3705,8 @@ SignBase::Error Sign::SignUpdate(const char* data, int len) {
 void Sign::SignUpdate(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  Sign* sign = Unwrap<Sign>(args.Holder());
+  Sign* sign;
+  ASSIGN_OR_RETURN_UNWRAP(&sign, args.Holder());
 
   THROW_AND_RETURN_IF_NOT_STRING_OR_BUFFER(args[0]);
 
@@ -3732,7 +3800,8 @@ SignBase::Error Sign::SignFinal(const char* key_pem,
 void Sign::SignFinal(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  Sign* sign = Unwrap<Sign>(args.Holder());
+  Sign* sign;
+  ASSIGN_OR_RETURN_UNWRAP(&sign, args.Holder());
 
   unsigned char* md_value;
   unsigned int md_len;
@@ -3815,7 +3884,8 @@ SignBase::Error Verify::VerifyInit(const char* verify_type) {
 
 
 void Verify::VerifyInit(const FunctionCallbackInfo<Value>& args) {
-  Verify* verify = Unwrap<Verify>(args.Holder());
+  Verify* verify;
+  ASSIGN_OR_RETURN_UNWRAP(&verify, args.Holder());
 
   if (args.Length() == 0 || !args[0]->IsString()) {
     return verify->env()->ThrowError("Must give verifytype string as argument");
@@ -3840,7 +3910,8 @@ SignBase::Error Verify::VerifyUpdate(const char* data, int len) {
 void Verify::VerifyUpdate(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  Verify* verify = Unwrap<Verify>(args.Holder());
+  Verify* verify;
+  ASSIGN_OR_RETURN_UNWRAP(&verify, args.Holder());
 
   THROW_AND_RETURN_IF_NOT_STRING_OR_BUFFER(args[0]);
 
@@ -3939,7 +4010,8 @@ SignBase::Error Verify::VerifyFinal(const char* key_pem,
 void Verify::VerifyFinal(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  Verify* verify = Unwrap<Verify>(args.Holder());
+  Verify* verify;
+  ASSIGN_OR_RETURN_UNWRAP(&verify, args.Holder());
 
   THROW_AND_RETURN_IF_NOT_BUFFER(args[0]);
   char* kbuf = Buffer::Data(args[0]);
@@ -4280,7 +4352,8 @@ void DiffieHellman::New(const FunctionCallbackInfo<Value>& args) {
 void DiffieHellman::GenerateKeys(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
+  DiffieHellman* diffieHellman;
+  ASSIGN_OR_RETURN_UNWRAP(&diffieHellman, args.Holder());
 
   if (!diffieHellman->initialised_) {
     return ThrowCryptoError(env, ERR_get_error(), "Not initialized");
@@ -4303,7 +4376,8 @@ void DiffieHellman::GenerateKeys(const FunctionCallbackInfo<Value>& args) {
 void DiffieHellman::GetPrime(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
+  DiffieHellman* diffieHellman;
+  ASSIGN_OR_RETURN_UNWRAP(&diffieHellman, args.Holder());
 
   if (!diffieHellman->initialised_) {
     return ThrowCryptoError(env, ERR_get_error(), "Not initialized");
@@ -4321,7 +4395,8 @@ void DiffieHellman::GetPrime(const FunctionCallbackInfo<Value>& args) {
 void DiffieHellman::GetGenerator(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
+  DiffieHellman* diffieHellman;
+  ASSIGN_OR_RETURN_UNWRAP(&diffieHellman, args.Holder());
 
   if (!diffieHellman->initialised_) {
     return ThrowCryptoError(env, ERR_get_error(), "Not initialized");
@@ -4339,7 +4414,8 @@ void DiffieHellman::GetGenerator(const FunctionCallbackInfo<Value>& args) {
 void DiffieHellman::GetPublicKey(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
+  DiffieHellman* diffieHellman;
+  ASSIGN_OR_RETURN_UNWRAP(&diffieHellman, args.Holder());
 
   if (!diffieHellman->initialised_) {
     return ThrowCryptoError(env, ERR_get_error(), "Not initialized");
@@ -4362,7 +4438,8 @@ void DiffieHellman::GetPublicKey(const FunctionCallbackInfo<Value>& args) {
 void DiffieHellman::GetPrivateKey(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
+  DiffieHellman* diffieHellman;
+  ASSIGN_OR_RETURN_UNWRAP(&diffieHellman, args.Holder());
 
   if (!diffieHellman->initialised_) {
     return ThrowCryptoError(env, ERR_get_error(), "Not initialized");
@@ -4385,7 +4462,8 @@ void DiffieHellman::GetPrivateKey(const FunctionCallbackInfo<Value>& args) {
 void DiffieHellman::ComputeSecret(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
+  DiffieHellman* diffieHellman;
+  ASSIGN_OR_RETURN_UNWRAP(&diffieHellman, args.Holder());
 
   if (!diffieHellman->initialised_) {
     return ThrowCryptoError(env, ERR_get_error(), "Not initialized");
@@ -4454,7 +4532,8 @@ void DiffieHellman::ComputeSecret(const FunctionCallbackInfo<Value>& args) {
 
 
 void DiffieHellman::SetPublicKey(const FunctionCallbackInfo<Value>& args) {
-  DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
+  DiffieHellman* diffieHellman;
+  ASSIGN_OR_RETURN_UNWRAP(&diffieHellman, args.Holder());
   Environment* env = diffieHellman->env();
 
   if (!diffieHellman->initialised_) {
@@ -4473,7 +4552,8 @@ void DiffieHellman::SetPublicKey(const FunctionCallbackInfo<Value>& args) {
 
 
 void DiffieHellman::SetPrivateKey(const FunctionCallbackInfo<Value>& args) {
-  DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
+  DiffieHellman* diffieHellman;
+  ASSIGN_OR_RETURN_UNWRAP(&diffieHellman, args.Holder());
   Environment* env = diffieHellman->env();
 
   if (!diffieHellman->initialised_) {
@@ -4496,7 +4576,8 @@ void DiffieHellman::VerifyErrorGetter(Local<String> property,
                                       const PropertyCallbackInfo<Value>& args) {
   HandleScope scope(args.GetIsolate());
 
-  DiffieHellman* diffieHellman = Unwrap<DiffieHellman>(args.Holder());
+  DiffieHellman* diffieHellman;
+  ASSIGN_OR_RETURN_UNWRAP(&diffieHellman, args.Holder());
 
   if (!diffieHellman->initialised_)
     return ThrowCryptoError(diffieHellman->env(), ERR_get_error(),
@@ -4558,7 +4639,8 @@ void ECDH::New(const FunctionCallbackInfo<Value>& args) {
 void ECDH::GenerateKeys(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  ECDH* ecdh = Unwrap<ECDH>(args.Holder());
+  ECDH* ecdh;
+  ASSIGN_OR_RETURN_UNWRAP(&ecdh, args.Holder());
 
   if (!EC_KEY_generate_key(ecdh->key_))
     return env->ThrowError("Failed to generate EC_KEY");
@@ -4601,7 +4683,8 @@ void ECDH::ComputeSecret(const FunctionCallbackInfo<Value>& args) {
 
   THROW_AND_RETURN_IF_NOT_BUFFER(args[0]);
 
-  ECDH* ecdh = Unwrap<ECDH>(args.Holder());
+  ECDH* ecdh;
+  ASSIGN_OR_RETURN_UNWRAP(&ecdh, args.Holder());
 
   EC_POINT* pub = ecdh->BufferToPoint(Buffer::Data(args[0]),
                                       Buffer::Length(args[0]));
@@ -4632,7 +4715,8 @@ void ECDH::GetPublicKey(const FunctionCallbackInfo<Value>& args) {
   // Conversion form
   CHECK_EQ(args.Length(), 1);
 
-  ECDH* ecdh = Unwrap<ECDH>(args.Holder());
+  ECDH* ecdh;
+  ASSIGN_OR_RETURN_UNWRAP(&ecdh, args.Holder());
 
   if (!ecdh->generated_)
     return env->ThrowError("You should generate ECDH keys first");
@@ -4667,7 +4751,8 @@ void ECDH::GetPublicKey(const FunctionCallbackInfo<Value>& args) {
 void ECDH::GetPrivateKey(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  ECDH* ecdh = Unwrap<ECDH>(args.Holder());
+  ECDH* ecdh;
+  ASSIGN_OR_RETURN_UNWRAP(&ecdh, args.Holder());
 
   if (!ecdh->generated_)
     return env->ThrowError("You should generate ECDH keys first");
@@ -4694,7 +4779,8 @@ void ECDH::GetPrivateKey(const FunctionCallbackInfo<Value>& args) {
 void ECDH::SetPrivateKey(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  ECDH* ecdh = Unwrap<ECDH>(args.Holder());
+  ECDH* ecdh;
+  ASSIGN_OR_RETURN_UNWRAP(&ecdh, args.Holder());
 
   THROW_AND_RETURN_IF_NOT_BUFFER(args[0]);
 
@@ -4717,7 +4803,8 @@ void ECDH::SetPrivateKey(const FunctionCallbackInfo<Value>& args) {
 void ECDH::SetPublicKey(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  ECDH* ecdh = Unwrap<ECDH>(args.Holder());
+  ECDH* ecdh;
+  ASSIGN_OR_RETURN_UNWRAP(&ecdh, args.Holder());
 
   THROW_AND_RETURN_IF_NOT_BUFFER(args[0]);
 
diff --git a/src/node_http_parser.cc b/src/node_http_parser.cc
index b12dd47706fe41..23344b385b0dad 100644
--- a/src/node_http_parser.cc
+++ b/src/node_http_parser.cc
@@ -369,7 +369,8 @@ class Parser : public AsyncWrap {
 
 
   static void Close(const FunctionCallbackInfo<Value>& args) {
-    Parser* parser = Unwrap<Parser>(args.Holder());
+    Parser* parser;
+    ASSIGN_OR_RETURN_UNWRAP(&parser, args.Holder());
 
     if (--parser->refcount_ == 0)
       delete parser;
@@ -392,7 +393,8 @@ class Parser : public AsyncWrap {
 
   // var bytesParsed = parser->execute(buffer);
   static void Execute(const FunctionCallbackInfo<Value>& args) {
-    Parser* parser = Unwrap<Parser>(args.Holder());
+    Parser* parser;
+    ASSIGN_OR_RETURN_UNWRAP(&parser, args.Holder());
     CHECK(parser->current_buffer_.IsEmpty());
     CHECK_EQ(parser->current_buffer_len_, 0);
     CHECK_EQ(parser->current_buffer_data_, nullptr);
@@ -417,7 +419,8 @@ class Parser : public AsyncWrap {
   static void Finish(const FunctionCallbackInfo<Value>& args) {
     Environment* env = Environment::GetCurrent(args);
 
-    Parser* parser = Unwrap<Parser>(args.Holder());
+    Parser* parser;
+    ASSIGN_OR_RETURN_UNWRAP(&parser, args.Holder());
 
     CHECK(parser->current_buffer_.IsEmpty());
     parser->got_exception_ = false;
@@ -448,7 +451,8 @@ class Parser : public AsyncWrap {
         static_cast<http_parser_type>(args[0]->Int32Value());
 
     CHECK(type == HTTP_REQUEST || type == HTTP_RESPONSE);
-    Parser* parser = Unwrap<Parser>(args.Holder());
+    Parser* parser;
+    ASSIGN_OR_RETURN_UNWRAP(&parser, args.Holder());
     // Should always be called from the same context.
     CHECK_EQ(env, parser->env());
     parser->Init(type);
@@ -458,7 +462,8 @@ class Parser : public AsyncWrap {
   template <bool should_pause>
   static void Pause(const FunctionCallbackInfo<Value>& args) {
     Environment* env = Environment::GetCurrent(args);
-    Parser* parser = Unwrap<Parser>(args.Holder());
+    Parser* parser;
+    ASSIGN_OR_RETURN_UNWRAP(&parser, args.Holder());
     // Should always be called from the same context.
     CHECK_EQ(env, parser->env());
     http_parser_pause(&parser->parser_, should_pause);
@@ -466,7 +471,8 @@ class Parser : public AsyncWrap {
 
 
   static void Consume(const FunctionCallbackInfo<Value>& args) {
-    Parser* parser = Unwrap<Parser>(args.Holder());
+    Parser* parser;
+    ASSIGN_OR_RETURN_UNWRAP(&parser, args.Holder());
     Local<External> stream_obj = args[0].As<External>();
     StreamBase* stream = static_cast<StreamBase*>(stream_obj->Value());
     CHECK_NE(stream, nullptr);
@@ -482,7 +488,8 @@ class Parser : public AsyncWrap {
 
 
   static void Unconsume(const FunctionCallbackInfo<Value>& args) {
-    Parser* parser = Unwrap<Parser>(args.Holder());
+    Parser* parser;
+    ASSIGN_OR_RETURN_UNWRAP(&parser, args.Holder());
 
     // Already unconsumed
     if (parser->prev_alloc_cb_.is_empty())
@@ -504,7 +511,8 @@ class Parser : public AsyncWrap {
 
 
   static void GetCurrentBuffer(const FunctionCallbackInfo<Value>& args) {
-    Parser* parser = Unwrap<Parser>(args.Holder());
+    Parser* parser;
+    ASSIGN_OR_RETURN_UNWRAP(&parser, args.Holder());
 
     Local<Object> ret = Buffer::Copy(
         parser->env(),
diff --git a/src/node_internals.h b/src/node_internals.h
index ef3af51018c9a0..62bf1c463831a7 100644
--- a/src/node_internals.h
+++ b/src/node_internals.h
@@ -80,6 +80,8 @@ v8::Local<v8::Object> AddressToJS(
 template <typename T, int (*F)(const typename T::HandleType*, sockaddr*, int*)>
 void GetSockOrPeerName(const v8::FunctionCallbackInfo<v8::Value>& args) {
   T* const wrap = Unwrap<T>(args.Holder());
+  if (wrap == nullptr)
+    return args.GetReturnValue().Set(UV_EBADF);
   CHECK(args[0]->IsObject());
   sockaddr_storage storage;
   int addrlen = sizeof(storage);
diff --git a/src/node_stat_watcher.cc b/src/node_stat_watcher.cc
index 4fa01794f6c6da..cff92e34045a1e 100644
--- a/src/node_stat_watcher.cc
+++ b/src/node_stat_watcher.cc
@@ -84,7 +84,8 @@ void StatWatcher::New(const FunctionCallbackInfo<Value>& args) {
 void StatWatcher::Start(const FunctionCallbackInfo<Value>& args) {
   CHECK_EQ(args.Length(), 3);
 
-  StatWatcher* wrap = Unwrap<StatWatcher>(args.Holder());
+  StatWatcher* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
   node::Utf8Value path(args.GetIsolate(), args[0]);
   const bool persistent = args[1]->BooleanValue();
   const uint32_t interval = args[2]->Uint32Value();
@@ -97,7 +98,8 @@ void StatWatcher::Start(const FunctionCallbackInfo<Value>& args) {
 
 
 void StatWatcher::Stop(const FunctionCallbackInfo<Value>& args) {
-  StatWatcher* wrap = Unwrap<StatWatcher>(args.Holder());
+  StatWatcher* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
   Environment* env = wrap->env();
   Context::Scope context_scope(env->context());
   wrap->MakeCallback(env->onstop_string(), 0, nullptr);
diff --git a/src/node_wrap.h b/src/node_wrap.h
index d508a4a470f63c..b2d6af8ad55ff5 100644
--- a/src/node_wrap.h
+++ b/src/node_wrap.h
@@ -39,6 +39,8 @@ inline uv_stream_t* HandleToStream(Environment* env,
   v8::HandleScope scope(env->isolate());
 
   WITH_GENERIC_UV_STREAM(env, obj, {
+    if (wrap == nullptr)
+      return nullptr;
     return reinterpret_cast<uv_stream_t*>(wrap->UVHandle());
   }, {});
 
diff --git a/src/node_zlib.cc b/src/node_zlib.cc
index 3bdeee4e63923e..0b8f1e06f513b2 100644
--- a/src/node_zlib.cc
+++ b/src/node_zlib.cc
@@ -105,7 +105,8 @@ class ZCtx : public AsyncWrap {
 
 
   static void Close(const FunctionCallbackInfo<Value>& args) {
-    ZCtx* ctx = Unwrap<ZCtx>(args.Holder());
+    ZCtx* ctx;
+    ASSIGN_OR_RETURN_UNWRAP(&ctx, args.Holder());
     ctx->Close();
   }
 
@@ -115,7 +116,8 @@ class ZCtx : public AsyncWrap {
   static void Write(const FunctionCallbackInfo<Value>& args) {
     CHECK_EQ(args.Length(), 7);
 
-    ZCtx* ctx = Unwrap<ZCtx>(args.Holder());
+    ZCtx* ctx;
+    ASSIGN_OR_RETURN_UNWRAP(&ctx, args.Holder());
     CHECK(ctx->init_done_ && "write before init");
     CHECK(ctx->mode_ != NONE && "already finalized");
 
@@ -363,7 +365,8 @@ class ZCtx : public AsyncWrap {
     CHECK((args.Length() == 4 || args.Length() == 5) &&
            "init(windowBits, level, memLevel, strategy, [dictionary])");
 
-    ZCtx* ctx = Unwrap<ZCtx>(args.Holder());
+    ZCtx* ctx;
+    ASSIGN_OR_RETURN_UNWRAP(&ctx, args.Holder());
 
     int windowBits = args[0]->Uint32Value();
     CHECK((windowBits >= 8 && windowBits <= 15) && "invalid windowBits");
@@ -399,12 +402,14 @@ class ZCtx : public AsyncWrap {
 
   static void Params(const FunctionCallbackInfo<Value>& args) {
     CHECK(args.Length() == 2 && "params(level, strategy)");
-    ZCtx* ctx = Unwrap<ZCtx>(args.Holder());
+    ZCtx* ctx;
+    ASSIGN_OR_RETURN_UNWRAP(&ctx, args.Holder());
     Params(ctx, args[0]->Int32Value(), args[1]->Int32Value());
   }
 
   static void Reset(const FunctionCallbackInfo<Value> &args) {
-    ZCtx* ctx = Unwrap<ZCtx>(args.Holder());
+    ZCtx* ctx;
+    ASSIGN_OR_RETURN_UNWRAP(&ctx, args.Holder());
     Reset(ctx);
     SetDictionary(ctx);
   }
diff --git a/src/pipe_wrap.cc b/src/pipe_wrap.cc
index e3377d402f5ab1..5bcb40f5d37fe5 100644
--- a/src/pipe_wrap.cc
+++ b/src/pipe_wrap.cc
@@ -138,7 +138,8 @@ PipeWrap::PipeWrap(Environment* env,
 
 
 void PipeWrap::Bind(const FunctionCallbackInfo<Value>& args) {
-  PipeWrap* wrap = Unwrap<PipeWrap>(args.Holder());
+  PipeWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
   node::Utf8Value name(args.GetIsolate(), args[0]);
   int err = uv_pipe_bind(&wrap->handle_, *name);
   args.GetReturnValue().Set(err);
@@ -147,7 +148,8 @@ void PipeWrap::Bind(const FunctionCallbackInfo<Value>& args) {
 
 #ifdef _WIN32
 void PipeWrap::SetPendingInstances(const FunctionCallbackInfo<Value>& args) {
-  PipeWrap* wrap = Unwrap<PipeWrap>(args.Holder());
+  PipeWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
   int instances = args[0]->Int32Value();
   uv_pipe_pending_instances(&wrap->handle_, instances);
 }
@@ -155,7 +157,8 @@ void PipeWrap::SetPendingInstances(const FunctionCallbackInfo<Value>& args) {
 
 
 void PipeWrap::Listen(const FunctionCallbackInfo<Value>& args) {
-  PipeWrap* wrap = Unwrap<PipeWrap>(args.Holder());
+  PipeWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
   int backlog = args[0]->Int32Value();
   int err = uv_listen(reinterpret_cast<uv_stream_t*>(&wrap->handle_),
                       backlog,
@@ -191,7 +194,8 @@ void PipeWrap::OnConnection(uv_stream_t* handle, int status) {
   Local<Object> client_obj = Instantiate(env, pipe_wrap);
 
   // Unwrap the client javascript object.
-  PipeWrap* wrap = Unwrap<PipeWrap>(client_obj);
+  PipeWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, client_obj);
   uv_stream_t* client_handle = reinterpret_cast<uv_stream_t*>(&wrap->handle_);
   if (uv_accept(handle, client_handle))
     return;
@@ -242,7 +246,8 @@ void PipeWrap::AfterConnect(uv_connect_t* req, int status) {
 void PipeWrap::Open(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  PipeWrap* wrap = Unwrap<PipeWrap>(args.Holder());
+  PipeWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   int fd = args[0]->Int32Value();
 
@@ -256,7 +261,8 @@ void PipeWrap::Open(const FunctionCallbackInfo<Value>& args) {
 void PipeWrap::Connect(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  PipeWrap* wrap = Unwrap<PipeWrap>(args.Holder());
+  PipeWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   CHECK(args[0]->IsObject());
   CHECK(args[1]->IsString());
diff --git a/src/process_wrap.cc b/src/process_wrap.cc
index 3b98b4a3771b3b..c256c3158b57a9 100644
--- a/src/process_wrap.cc
+++ b/src/process_wrap.cc
@@ -85,6 +85,7 @@ class ProcessWrap : public HandleWrap {
             UV_CREATE_PIPE | UV_READABLE_PIPE | UV_WRITABLE_PIPE);
         Local<String> handle_key = env->handle_string();
         Local<Object> handle = stdio->Get(handle_key).As<Object>();
+        CHECK(!handle.IsEmpty());
         options->stdio[i].data.stream =
             reinterpret_cast<uv_stream_t*>(
                 Unwrap<PipeWrap>(handle)->UVHandle());
@@ -108,7 +109,8 @@ class ProcessWrap : public HandleWrap {
   static void Spawn(const FunctionCallbackInfo<Value>& args) {
     Environment* env = Environment::GetCurrent(args);
 
-    ProcessWrap* wrap = Unwrap<ProcessWrap>(args.Holder());
+    ProcessWrap* wrap;
+    ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
     Local<Object> js_options = args[0]->ToObject(env->isolate());
 
@@ -226,7 +228,8 @@ class ProcessWrap : public HandleWrap {
   }
 
   static void Kill(const FunctionCallbackInfo<Value>& args) {
-    ProcessWrap* wrap = Unwrap<ProcessWrap>(args.Holder());
+    ProcessWrap* wrap;
+    ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
     int signal = args[0]->Int32Value();
     int err = uv_process_kill(&wrap->process_, signal);
     args.GetReturnValue().Set(err);
diff --git a/src/signal_wrap.cc b/src/signal_wrap.cc
index 5f6a6a52bcd786..52669c9444e83f 100644
--- a/src/signal_wrap.cc
+++ b/src/signal_wrap.cc
@@ -61,14 +61,16 @@ class SignalWrap : public HandleWrap {
   }
 
   static void Start(const FunctionCallbackInfo<Value>& args) {
-    SignalWrap* wrap = Unwrap<SignalWrap>(args.Holder());
+    SignalWrap* wrap;
+    ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
     int signum = args[0]->Int32Value();
     int err = uv_signal_start(&wrap->handle_, OnSignal, signum);
     args.GetReturnValue().Set(err);
   }
 
   static void Stop(const FunctionCallbackInfo<Value>& args) {
-    SignalWrap* wrap = Unwrap<SignalWrap>(args.Holder());
+    SignalWrap* wrap;
+    ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
     int err = uv_signal_stop(&wrap->handle_);
     args.GetReturnValue().Set(err);
   }
diff --git a/src/stream_base-inl.h b/src/stream_base-inl.h
index e8e73f007ef712..bdc8211707388a 100644
--- a/src/stream_base-inl.h
+++ b/src/stream_base-inl.h
@@ -80,8 +80,9 @@ void StreamBase::GetFD(Local<String> key,
   Base* handle = Unwrap<Base>(args.Holder());
 
   // Mimic implementation of StreamBase::GetFD() and UDPWrap::GetFD().
-  if (handle == nullptr)
-    return args.GetReturnValue().Set(-1);
+  ASSIGN_OR_RETURN_UNWRAP(&handle,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EINVAL));
 
   StreamBase* wrap = static_cast<StreamBase*>(handle);
   if (!wrap->IsAlive())
@@ -97,8 +98,9 @@ void StreamBase::GetBytesRead(Local<String> key,
   Base* handle = Unwrap<Base>(args.Holder());
 
   // The handle instance hasn't been set. So no bytes could have been read.
-  if (handle == nullptr)
-    return args.GetReturnValue().Set(0);
+  ASSIGN_OR_RETURN_UNWRAP(&handle,
+                          args.Holder(),
+                          args.GetReturnValue().Set(0));
 
   StreamBase* wrap = static_cast<StreamBase*>(handle);
   // uint64_t -> double. 53bits is enough for all real cases.
@@ -111,8 +113,7 @@ void StreamBase::GetExternal(Local<String> key,
                              const PropertyCallbackInfo<Value>& args) {
   Base* handle = Unwrap<Base>(args.Holder());
 
-  if (handle == nullptr)
-    return args.GetReturnValue().SetUndefined();
+  ASSIGN_OR_RETURN_UNWRAP(&handle, args.Holder());
 
   StreamBase* wrap = static_cast<StreamBase*>(handle);
   Local<External> ext = External::New(args.GetIsolate(), wrap);
@@ -125,8 +126,7 @@ template <class Base,
 void StreamBase::JSMethod(const FunctionCallbackInfo<Value>& args) {
   Base* handle = Unwrap<Base>(args.Holder());
 
-  if (handle == nullptr)
-    return args.GetReturnValue().SetUndefined();
+  ASSIGN_OR_RETURN_UNWRAP(&handle, args.Holder());
 
   StreamBase* wrap = static_cast<StreamBase*>(handle);
   if (!wrap->IsAlive())
diff --git a/src/stream_base.cc b/src/stream_base.cc
index 8573d1c1c8f34d..ccad302d7c1615 100644
--- a/src/stream_base.cc
+++ b/src/stream_base.cc
@@ -328,7 +328,8 @@ int StreamBase::WriteString(const FunctionCallbackInfo<Value>& args) {
     uv_handle_t* send_handle = nullptr;
 
     if (!send_handle_obj.IsEmpty()) {
-      HandleWrap* wrap = Unwrap<HandleWrap>(send_handle_obj);
+      HandleWrap* wrap;
+      ASSIGN_OR_RETURN_UNWRAP(&wrap, send_handle_obj, UV_EINVAL);
       send_handle = wrap->GetHandle();
       // Reference StreamWrap instance to prevent it from being garbage
       // collected before `AfterWrite` is called.
diff --git a/src/stream_wrap.cc b/src/stream_wrap.cc
index 7118a9e573f4c2..56012e67a55144 100644
--- a/src/stream_wrap.cc
+++ b/src/stream_wrap.cc
@@ -175,7 +175,8 @@ static Local<Object> AcceptHandle(Environment* env, StreamWrap* parent) {
   if (wrap_obj.IsEmpty())
     return Local<Object>();
 
-  WrapType* wrap = Unwrap<WrapType>(wrap_obj);
+  WrapType* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, wrap_obj, Local<Object>());
   handle = wrap->UVHandle();
 
   if (uv_accept(parent->stream(), reinterpret_cast<uv_stream_t*>(handle)))
@@ -267,7 +268,8 @@ void StreamWrap::OnRead(uv_stream_t* handle,
 
 
 void StreamWrap::SetBlocking(const FunctionCallbackInfo<Value>& args) {
-  StreamWrap* wrap = Unwrap<StreamWrap>(args.Holder());
+  StreamWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   CHECK_GT(args.Length(), 0);
   if (!wrap->IsAlive())
diff --git a/src/tcp_wrap.cc b/src/tcp_wrap.cc
index 0214be100228c4..4028581164bae9 100644
--- a/src/tcp_wrap.cc
+++ b/src/tcp_wrap.cc
@@ -164,7 +164,10 @@ TCPWrap::~TCPWrap() {
 
 
 void TCPWrap::SetNoDelay(const FunctionCallbackInfo<Value>& args) {
-  TCPWrap* wrap = Unwrap<TCPWrap>(args.Holder());
+  TCPWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
   int enable = static_cast<int>(args[0]->BooleanValue());
   int err = uv_tcp_nodelay(&wrap->handle_, enable);
   args.GetReturnValue().Set(err);
@@ -172,7 +175,10 @@ void TCPWrap::SetNoDelay(const FunctionCallbackInfo<Value>& args) {
 
 
 void TCPWrap::SetKeepAlive(const FunctionCallbackInfo<Value>& args) {
-  TCPWrap* wrap = Unwrap<TCPWrap>(args.Holder());
+  TCPWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
   int enable = args[0]->Int32Value();
   unsigned int delay = args[1]->Uint32Value();
   int err = uv_tcp_keepalive(&wrap->handle_, enable, delay);
@@ -182,7 +188,10 @@ void TCPWrap::SetKeepAlive(const FunctionCallbackInfo<Value>& args) {
 
 #ifdef _WIN32
 void TCPWrap::SetSimultaneousAccepts(const FunctionCallbackInfo<Value>& args) {
-  TCPWrap* wrap = Unwrap<TCPWrap>(args.Holder());
+  TCPWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
   bool enable = args[0]->BooleanValue();
   int err = uv_tcp_simultaneous_accepts(&wrap->handle_, enable);
   args.GetReturnValue().Set(err);
@@ -191,14 +200,20 @@ void TCPWrap::SetSimultaneousAccepts(const FunctionCallbackInfo<Value>& args) {
 
 
 void TCPWrap::Open(const FunctionCallbackInfo<Value>& args) {
-  TCPWrap* wrap = Unwrap<TCPWrap>(args.Holder());
+  TCPWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
   int fd = static_cast<int>(args[0]->IntegerValue());
   uv_tcp_open(&wrap->handle_, fd);
 }
 
 
 void TCPWrap::Bind(const FunctionCallbackInfo<Value>& args) {
-  TCPWrap* wrap = Unwrap<TCPWrap>(args.Holder());
+  TCPWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
   node::Utf8Value ip_address(args.GetIsolate(), args[0]);
   int port = args[1]->Int32Value();
   sockaddr_in addr;
@@ -213,7 +228,10 @@ void TCPWrap::Bind(const FunctionCallbackInfo<Value>& args) {
 
 
 void TCPWrap::Bind6(const FunctionCallbackInfo<Value>& args) {
-  TCPWrap* wrap = Unwrap<TCPWrap>(args.Holder());
+  TCPWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
   node::Utf8Value ip6_address(args.GetIsolate(), args[0]);
   int port = args[1]->Int32Value();
   sockaddr_in6 addr;
@@ -228,7 +246,10 @@ void TCPWrap::Bind6(const FunctionCallbackInfo<Value>& args) {
 
 
 void TCPWrap::Listen(const FunctionCallbackInfo<Value>& args) {
-  TCPWrap* wrap = Unwrap<TCPWrap>(args.Holder());
+  TCPWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
   int backlog = args[0]->Int32Value();
   int err = uv_listen(reinterpret_cast<uv_stream_t*>(&wrap->handle_),
                       backlog,
@@ -261,6 +282,7 @@ void TCPWrap::OnConnection(uv_stream_t* handle, int status) {
 
     // Unwrap the client javascript object.
     TCPWrap* wrap = Unwrap<TCPWrap>(client_obj);
+    CHECK_NE(wrap, nullptr);
     uv_stream_t* client_handle = reinterpret_cast<uv_stream_t*>(&wrap->handle_);
     if (uv_accept(handle, client_handle))
       return;
@@ -304,7 +326,10 @@ void TCPWrap::AfterConnect(uv_connect_t* req, int status) {
 void TCPWrap::Connect(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  TCPWrap* wrap = Unwrap<TCPWrap>(args.Holder());
+  TCPWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
 
   CHECK(args[0]->IsObject());
   CHECK(args[1]->IsString());
@@ -335,7 +360,10 @@ void TCPWrap::Connect(const FunctionCallbackInfo<Value>& args) {
 void TCPWrap::Connect6(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  TCPWrap* wrap = Unwrap<TCPWrap>(args.Holder());
+  TCPWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
 
   CHECK(args[0]->IsObject());
   CHECK(args[1]->IsString());
diff --git a/src/tls_wrap.cc b/src/tls_wrap.cc
index 0b12258d8b40da..116a379337ef57 100644
--- a/src/tls_wrap.cc
+++ b/src/tls_wrap.cc
@@ -55,6 +55,9 @@ TLSWrap::TLSWrap(Environment* env,
   node::Wrap(object(), this);
   MakeWeak(this);
 
+  // sc comes from an Unwrap. Make sure it was assigned.
+  CHECK_NE(sc, nullptr);
+
   // We've our own session callbacks
   SSL_CTX_sess_set_get_cb(sc_->ctx_, SSLWrap<TLSWrap>::GetSessionCallback);
   SSL_CTX_sess_set_new_cb(sc_->ctx_, SSLWrap<TLSWrap>::NewSessionCallback);
@@ -189,7 +192,8 @@ void TLSWrap::Wrap(const FunctionCallbackInfo<Value>& args) {
 
 
 void TLSWrap::Receive(const FunctionCallbackInfo<Value>& args) {
-  TLSWrap* wrap = Unwrap<TLSWrap>(args.Holder());
+  TLSWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   CHECK(Buffer::HasInstance(args[0]));
   char* data = Buffer::Data(args[0]);
@@ -214,7 +218,8 @@ void TLSWrap::Receive(const FunctionCallbackInfo<Value>& args) {
 void TLSWrap::Start(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  TLSWrap* wrap = Unwrap<TLSWrap>(args.Holder());
+  TLSWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   if (wrap->started_)
     return env->ThrowError("Already started.");
@@ -731,7 +736,8 @@ int TLSWrap::DoShutdown(ShutdownWrap* req_wrap) {
 void TLSWrap::SetVerifyMode(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  TLSWrap* wrap = Unwrap<TLSWrap>(args.Holder());
+  TLSWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   if (args.Length() < 2 || !args[0]->IsBoolean() || !args[1]->IsBoolean())
     return env->ThrowTypeError("Bad arguments, expected two booleans");
@@ -763,7 +769,8 @@ void TLSWrap::SetVerifyMode(const FunctionCallbackInfo<Value>& args) {
 
 void TLSWrap::EnableSessionCallbacks(
     const FunctionCallbackInfo<Value>& args) {
-  TLSWrap* wrap = Unwrap<TLSWrap>(args.Holder());
+  TLSWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
   if (wrap->ssl_ == nullptr) {
     return wrap->env()->ThrowTypeError(
         "EnableSessionCallbacks after destroySSL");
@@ -777,7 +784,8 @@ void TLSWrap::EnableSessionCallbacks(
 
 
 void TLSWrap::DestroySSL(const FunctionCallbackInfo<Value>& args) {
-  TLSWrap* wrap = Unwrap<TLSWrap>(args.Holder());
+  TLSWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   // Move all writes to pending
   wrap->MakePending();
@@ -794,7 +802,8 @@ void TLSWrap::DestroySSL(const FunctionCallbackInfo<Value>& args) {
 
 
 void TLSWrap::EnableCertCb(const FunctionCallbackInfo<Value>& args) {
-  TLSWrap* wrap = Unwrap<TLSWrap>(args.Holder());
+  TLSWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
   wrap->WaitForCertCb(OnClientHelloParseEnd, wrap);
 }
 
@@ -809,7 +818,8 @@ void TLSWrap::OnClientHelloParseEnd(void* arg) {
 void TLSWrap::GetServername(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  TLSWrap* wrap = Unwrap<TLSWrap>(args.Holder());
+  TLSWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   CHECK_NE(wrap->ssl_, nullptr);
 
@@ -826,7 +836,8 @@ void TLSWrap::GetServername(const FunctionCallbackInfo<Value>& args) {
 void TLSWrap::SetServername(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  TLSWrap* wrap = Unwrap<TLSWrap>(args.Holder());
+  TLSWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap, args.Holder());
 
   if (args.Length() < 1 || !args[0]->IsString())
     return env->ThrowTypeError("First argument should be a string");
@@ -875,6 +886,7 @@ int TLSWrap::SelectSNIContextCallback(SSL* s, int* ad, void* arg) {
   p->sni_context_.Reset(env->isolate(), ctx);
 
   SecureContext* sc = Unwrap<SecureContext>(ctx.As<Object>());
+  CHECK_NE(sc, nullptr);
   p->SetSNIContext(sc);
   return SSL_TLSEXT_ERR_OK;
 }
diff --git a/src/tty_wrap.cc b/src/tty_wrap.cc
index a78d2311456c7c..7faeb0534b673c 100644
--- a/src/tty_wrap.cc
+++ b/src/tty_wrap.cc
@@ -90,7 +90,10 @@ void TTYWrap::IsTTY(const FunctionCallbackInfo<Value>& args) {
 void TTYWrap::GetWindowSize(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  TTYWrap* wrap = Unwrap<TTYWrap>(args.Holder());
+  TTYWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
   CHECK(args[0]->IsArray());
 
   int width, height;
@@ -107,7 +110,10 @@ void TTYWrap::GetWindowSize(const FunctionCallbackInfo<Value>& args) {
 
 
 void TTYWrap::SetRawMode(const FunctionCallbackInfo<Value>& args) {
-  TTYWrap* wrap = Unwrap<TTYWrap>(args.Holder());
+  TTYWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
   int err = uv_tty_set_mode(&wrap->handle_, args[0]->IsTrue());
   args.GetReturnValue().Set(err);
 }
diff --git a/src/udp_wrap.cc b/src/udp_wrap.cc
index e0f51cbf589699..57238534c4a30e 100644
--- a/src/udp_wrap.cc
+++ b/src/udp_wrap.cc
@@ -136,7 +136,7 @@ void UDPWrap::New(const FunctionCallbackInfo<Value>& args) {
 
 
 void UDPWrap::GetFD(Local<String>, const PropertyCallbackInfo<Value>& args) {
-  int fd = -1;
+  int fd = UV_EBADF;
 #if !defined(_WIN32)
   HandleScope scope(args.GetIsolate());
   UDPWrap* wrap = Unwrap<UDPWrap>(args.Holder());
@@ -148,7 +148,10 @@ void UDPWrap::GetFD(Local<String>, const PropertyCallbackInfo<Value>& args) {
 
 
 void UDPWrap::DoBind(const FunctionCallbackInfo<Value>& args, int family) {
-  UDPWrap* wrap = Unwrap<UDPWrap>(args.Holder());
+  UDPWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
 
   // bind(ip, port, flags)
   CHECK_EQ(args.Length(), 3);
@@ -196,7 +199,7 @@ void UDPWrap::Bind6(const FunctionCallbackInfo<Value>& args) {
     UDPWrap* wrap = Unwrap<UDPWrap>(args.Holder());                           \
     CHECK_EQ(args.Length(), 1);                                               \
     int flag = args[0]->Int32Value();                                         \
-    int err = fn(&wrap->handle_, flag);                                       \
+    int err = wrap == nullptr ? UV_EBADF : fn(&wrap->handle_, flag);          \
     args.GetReturnValue().Set(err);                                           \
   }
 
@@ -210,7 +213,10 @@ X(SetMulticastLoopback, uv_udp_set_multicast_loop)
 
 void UDPWrap::SetMembership(const FunctionCallbackInfo<Value>& args,
                             uv_membership membership) {
-  UDPWrap* wrap = Unwrap<UDPWrap>(args.Holder());
+  UDPWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
 
   CHECK_EQ(args.Length(), 2);
 
@@ -243,7 +249,10 @@ void UDPWrap::DropMembership(const FunctionCallbackInfo<Value>& args) {
 void UDPWrap::DoSend(const FunctionCallbackInfo<Value>& args, int family) {
   Environment* env = Environment::GetCurrent(args);
 
-  UDPWrap* wrap = Unwrap<UDPWrap>(args.Holder());
+  UDPWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
 
   // send(req, buffer, offset, length, port, address)
   CHECK(args[0]->IsObject());
@@ -311,7 +320,10 @@ void UDPWrap::Send6(const FunctionCallbackInfo<Value>& args) {
 
 
 void UDPWrap::RecvStart(const FunctionCallbackInfo<Value>& args) {
-  UDPWrap* wrap = Unwrap<UDPWrap>(args.Holder());
+  UDPWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
   int err = uv_udp_recv_start(&wrap->handle_, OnAlloc, OnRecv);
   // UV_EALREADY means that the socket is already bound but that's okay
   if (err == UV_EALREADY)
@@ -321,7 +333,10 @@ void UDPWrap::RecvStart(const FunctionCallbackInfo<Value>& args) {
 
 
 void UDPWrap::RecvStop(const FunctionCallbackInfo<Value>& args) {
-  UDPWrap* wrap = Unwrap<UDPWrap>(args.Holder());
+  UDPWrap* wrap;
+  ASSIGN_OR_RETURN_UNWRAP(&wrap,
+                          args.Holder(),
+                          args.GetReturnValue().Set(UV_EBADF));
   int r = uv_udp_recv_stop(&wrap->handle_);
   args.GetReturnValue().Set(r);
 }
diff --git a/src/util.h b/src/util.h
index 1973f268e4ecac..e5de6f2207e3b0 100644
--- a/src/util.h
+++ b/src/util.h
@@ -16,6 +16,12 @@
 
 namespace node {
 
+#ifdef __APPLE__
+template <typename T> using remove_reference = std::tr1::remove_reference<T>;
+#else
+template <typename T> using remove_reference = std::remove_reference<T>;
+#endif
+
 #define FIXED_ONE_BYTE_STRING(isolate, string)                                \
   (node::OneByteString((isolate), (string), sizeof(string) - 1))
 
@@ -59,6 +65,14 @@ namespace node {
 
 #define UNREACHABLE() ABORT()
 
+#define ASSIGN_OR_RETURN_UNWRAP(ptr, obj, ...)                                \
+  do {                                                                        \
+    *ptr =                                                                    \
+        Unwrap<typename node::remove_reference<decltype(**ptr)>::type>(obj);  \
+    if (*ptr == nullptr)                                                      \
+      return __VA_ARGS__;                                                     \
+  } while (0)
+
 // TAILQ-style intrusive list node.
 template <typename T>
 class ListNode;
diff --git a/test/parallel/test-stream-base-no-abort.js b/test/parallel/test-stream-base-no-abort.js
new file mode 100644
index 00000000000000..d2d87026768d3c
--- /dev/null
+++ b/test/parallel/test-stream-base-no-abort.js
@@ -0,0 +1,58 @@
+'use strict';
+
+const async_wrap = process.binding('async_wrap');
+const uv = process.binding('uv');
+const assert = require('assert');
+const common = require('../common');
+const dgram = require('dgram');
+const fs = require('fs');
+const net = require('net');
+const tls = require('tls');
+const providers = Object.keys(async_wrap.Providers);
+var flags = 0;
+
+// Make sure all asserts have run at least once.
+process.on('exit', () => assert.equal(flags, 0b111));
+
+function init(id, provider) {
+  this._external;  // Test will abort if nullptr isn't properly checked.
+  switch (providers[provider]) {
+    case 'TCPWRAP':
+      assert.equal(this.fd, uv.UV_EINVAL);
+      flags |= 0b1;
+      break;
+    case 'TLSWRAP':
+      assert.equal(this.fd, uv.UV_EINVAL);
+      flags |= 0b10;
+      break;
+    case 'UDPWRAP':
+      assert.equal(this.fd, uv.UV_EBADF);
+      flags |= 0b100;
+      break;
+  }
+}
+
+async_wrap.setupHooks({ init });
+async_wrap.enable();
+
+const checkTLS = common.mustCall(function checkTLS() {
+  const options = {
+    key: fs.readFileSync(common.fixturesDir + '/keys/ec-key.pem'),
+    cert: fs.readFileSync(common.fixturesDir + '/keys/ec-cert.pem')
+  };
+  const server = tls.createServer(options, () => {})
+    .listen(common.PORT, function() {
+      tls.connect(common.PORT, { rejectUnauthorized: false }, function() {
+        this.destroy();
+        server.close();
+      });
+    });
+});
+
+const checkTCP = common.mustCall(function checkTCP() {
+  net.createServer(() => {}).listen(common.PORT, function() {
+    this.close(checkTLS);
+  });
+});
+
+dgram.createSocket('udp4').close(checkTCP);