diff --git a/BUILD.bazel b/BUILD.bazel
index bc587a0b2249..42175b5ed11e 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -12,7 +12,10 @@ load(":protobuf.bzl", "internal_objc_proto_library", "internal_php_proto_library
 
 licenses(["notice"])
 
-exports_files(["LICENSE"])
+exports_files([
+    "LICENSE",
+    "PrivacyInfo.xcprivacy",
+])
 
 ################################################################################
 # Well Known Types Proto Library Rules
diff --git a/upb/reflection/field_def.c b/upb/reflection/field_def.c
index c18f62184183..9f2775b8699f 100644
--- a/upb/reflection/field_def.c
+++ b/upb/reflection/field_def.c
@@ -648,7 +648,7 @@ static void _upb_FieldDef_Create(upb_DefBuilder* ctx, const char* prefix,
                            f->full_name);
     }
 
-    if (oneof_index >= upb_MessageDef_OneofCount(m)) {
+    if (oneof_index < 0 || oneof_index >= upb_MessageDef_OneofCount(m)) {
       _upb_DefBuilder_Errf(ctx, "oneof_index out of range (%s)", f->full_name);
     }
 
diff --git a/upb/util/def_to_proto_test.cc b/upb/util/def_to_proto_test.cc
index 0c7b2038f4bc..e14b8c4d154d 100644
--- a/upb/util/def_to_proto_test.cc
+++ b/upb/util/def_to_proto_test.cc
@@ -333,4 +333,15 @@ TEST(FuzzTest, RoundTripDescriptorRegressionOneofSameName) {
            })pb"));
 }
 
+TEST(FuzzTest, NegativeOneofIndex) {
+  RoundTripDescriptor(ParseTextProtoOrDie(
+      R"pb(file {
+             message_type {
+               name: "A"
+               field { name: "A" number: 0 type_name: "" oneof_index: -1 }
+             }
+           }
+      )pb"));
+}
+
 }  // namespace upb_test