diff --git a/packages/api/package.json b/packages/api/package.json
index d495732cbc62..f87de28f0882 100644
--- a/packages/api/package.json
+++ b/packages/api/package.json
@@ -70,7 +70,7 @@
   },
   "dependencies": {
     "@chainsafe/persistent-merkle-tree": "^0.5.0",
-    "@chainsafe/ssz": "^0.12.0",
+    "@chainsafe/ssz": "^0.13.0",
     "@lodestar/config": "^1.11.1",
     "@lodestar/params": "^1.11.1",
     "@lodestar/types": "^1.11.1",
diff --git a/packages/beacon-node/package.json b/packages/beacon-node/package.json
index ec993ccc1e42..44759696641a 100644
--- a/packages/beacon-node/package.json
+++ b/packages/beacon-node/package.json
@@ -104,7 +104,7 @@
     "@chainsafe/libp2p-noise": "^13.0.0",
     "@chainsafe/persistent-merkle-tree": "^0.5.0",
     "@chainsafe/prometheus-gc-stats": "^1.0.0",
-    "@chainsafe/ssz": "^0.12.0",
+    "@chainsafe/ssz": "^0.13.0",
     "@chainsafe/threads": "^1.11.1",
     "@ethersproject/abi": "^5.7.0",
     "@fastify/bearer-auth": "^9.0.0",
diff --git a/packages/beacon-node/src/util/sszBytes.ts b/packages/beacon-node/src/util/sszBytes.ts
index 46c28f7948fa..0c258df35041 100644
--- a/packages/beacon-node/src/util/sszBytes.ts
+++ b/packages/beacon-node/src/util/sszBytes.ts
@@ -1,4 +1,4 @@
-import {BitArray} from "@chainsafe/ssz";
+import {BitArray, deserializeUint8ArrayBitListFromBytes} from "@chainsafe/ssz";
 import {BLSSignature, RootHex, Slot} from "@lodestar/types";
 import {toHex} from "@lodestar/utils";
 
@@ -210,39 +210,3 @@ function getSlotFromOffset(data: Uint8Array, offset: number): Slot {
   // Read only the first 4 bytes of Slot, max value is 4,294,967,295 will be reached 1634 years after genesis
   return dv.getUint32(offset, true);
 }
-
-type BitArrayDeserialized = {uint8Array: Uint8Array; bitLen: number};
-
-/**
- * This is copied from ssz bitList.ts
- * TODO: export this util from there
- */
-function deserializeUint8ArrayBitListFromBytes(data: Uint8Array, start: number, end: number): BitArrayDeserialized {
-  if (end > data.length) {
-    throw Error(`BitList attempting to read byte ${end} of data length ${data.length}`);
-  }
-
-  const lastByte = data[end - 1];
-  const size = end - start;
-
-  if (lastByte === 0) {
-    throw new Error("Invalid deserialized bitlist, padding bit required");
-  }
-
-  if (lastByte === 1) {
-    // Buffer.prototype.slice does not copy memory, Enforce Uint8Array usage https://github.com/nodejs/node/issues/28087
-    const uint8Array = Uint8Array.prototype.slice.call(data, start, end - 1);
-    const bitLen = (size - 1) * 8;
-    return {uint8Array, bitLen};
-  }
-
-  // the last byte is > 1, so a padding bit will exist in the last byte and need to be removed
-  // Buffer.prototype.slice does not copy memory, Enforce Uint8Array usage https://github.com/nodejs/node/issues/28087
-  const uint8Array = Uint8Array.prototype.slice.call(data, start, end);
-  // mask lastChunkByte
-  const lastByteBitLength = lastByte.toString(2).length - 1;
-  const bitLen = (size - 1) * 8 + lastByteBitLength;
-  const mask = 0xff >> (8 - lastByteBitLength);
-  uint8Array[size - 1] &= mask;
-  return {uint8Array, bitLen};
-}
diff --git a/packages/cli/package.json b/packages/cli/package.json
index 3053484497bb..a4a387fc670b 100644
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -59,7 +59,7 @@
     "@chainsafe/bls-keystore": "^2.0.0",
     "@chainsafe/blst": "^0.2.9",
     "@chainsafe/discv5": "^5.1.0",
-    "@chainsafe/ssz": "^0.12.0",
+    "@chainsafe/ssz": "^0.13.0",
     "@chainsafe/threads": "^1.11.1",
     "@libp2p/crypto": "^2.0.2",
     "@libp2p/peer-id": "^3.0.1",
diff --git a/packages/config/package.json b/packages/config/package.json
index 7113b053f9d3..8fd9bd835b5c 100644
--- a/packages/config/package.json
+++ b/packages/config/package.json
@@ -64,7 +64,7 @@
     "blockchain"
   ],
   "dependencies": {
-    "@chainsafe/ssz": "^0.12.0",
+    "@chainsafe/ssz": "^0.13.0",
     "@lodestar/params": "^1.11.1",
     "@lodestar/types": "^1.11.1"
   }
diff --git a/packages/db/package.json b/packages/db/package.json
index ea9fecd69079..f9227668e829 100644
--- a/packages/db/package.json
+++ b/packages/db/package.json
@@ -37,7 +37,7 @@
     "check-readme": "typescript-docs-verifier"
   },
   "dependencies": {
-    "@chainsafe/ssz": "^0.12.0",
+    "@chainsafe/ssz": "^0.13.0",
     "@lodestar/config": "^1.11.1",
     "@lodestar/utils": "^1.11.1",
     "@types/levelup": "^4.3.3",
diff --git a/packages/fork-choice/package.json b/packages/fork-choice/package.json
index 8565da619c17..0e8de6bf52f5 100644
--- a/packages/fork-choice/package.json
+++ b/packages/fork-choice/package.json
@@ -38,7 +38,7 @@
     "check-readme": "typescript-docs-verifier"
   },
   "dependencies": {
-    "@chainsafe/ssz": "^0.12.0",
+    "@chainsafe/ssz": "^0.13.0",
     "@lodestar/config": "^1.11.1",
     "@lodestar/params": "^1.11.1",
     "@lodestar/state-transition": "^1.11.1",
diff --git a/packages/light-client/package.json b/packages/light-client/package.json
index 088a6f37909b..95bca9e36b29 100644
--- a/packages/light-client/package.json
+++ b/packages/light-client/package.json
@@ -66,7 +66,7 @@
   "dependencies": {
     "@chainsafe/bls": "7.1.1",
     "@chainsafe/persistent-merkle-tree": "^0.5.0",
-    "@chainsafe/ssz": "^0.12.0",
+    "@chainsafe/ssz": "^0.13.0",
     "@lodestar/api": "^1.11.1",
     "@lodestar/config": "^1.11.1",
     "@lodestar/params": "^1.11.1",
diff --git a/packages/state-transition/package.json b/packages/state-transition/package.json
index 0302f6f6eaaa..133e149188b7 100644
--- a/packages/state-transition/package.json
+++ b/packages/state-transition/package.json
@@ -61,7 +61,7 @@
     "@chainsafe/bls": "7.1.1",
     "@chainsafe/persistent-merkle-tree": "^0.5.0",
     "@chainsafe/persistent-ts": "^0.19.1",
-    "@chainsafe/ssz": "^0.12.0",
+    "@chainsafe/ssz": "^0.13.0",
     "@lodestar/config": "^1.11.1",
     "@lodestar/params": "^1.11.1",
     "@lodestar/types": "^1.11.1",
diff --git a/packages/types/package.json b/packages/types/package.json
index 5b7a730ef45d..45676cc616f0 100644
--- a/packages/types/package.json
+++ b/packages/types/package.json
@@ -67,7 +67,7 @@
   },
   "types": "lib/index.d.ts",
   "dependencies": {
-    "@chainsafe/ssz": "^0.12.0",
+    "@chainsafe/ssz": "^0.13.0",
     "@lodestar/params": "^1.11.1"
   },
   "keywords": [
diff --git a/packages/validator/package.json b/packages/validator/package.json
index f634989ac432..ed1433cf48c3 100644
--- a/packages/validator/package.json
+++ b/packages/validator/package.json
@@ -49,7 +49,7 @@
   ],
   "dependencies": {
     "@chainsafe/bls": "7.1.1",
-    "@chainsafe/ssz": "^0.12.0",
+    "@chainsafe/ssz": "^0.13.0",
     "@lodestar/api": "^1.11.1",
     "@lodestar/config": "^1.11.1",
     "@lodestar/db": "^1.11.1",
diff --git a/yarn.lock b/yarn.lock
index 4290e224919a..8d6155b15fec 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -644,10 +644,10 @@
     "@chainsafe/as-sha256" "^0.4.1"
     "@chainsafe/persistent-merkle-tree" "^0.6.1"
 
-"@chainsafe/ssz@^0.12.0":
-  version "0.12.0"
-  resolved "https://registry.yarnpkg.com/@chainsafe/ssz/-/ssz-0.12.0.tgz#60dbbd855d2d39d3bc032f44d18a094c364501ae"
-  integrity sha512-FZUvB7NsQBQc+/3+QSCaqHjKMAXs+M4NiFsskOcRVm1G2FN19u/Er+783YeIpX8Ld9mLplvn2qv33vQedcul0w==
+"@chainsafe/ssz@^0.13.0":
+  version "0.13.0"
+  resolved "https://registry.yarnpkg.com/@chainsafe/ssz/-/ssz-0.13.0.tgz#0bd11af6abe023d4cc24067a46889dcabbe573e5"
+  integrity sha512-73PF5bFXE9juLD1+dkmYV/CMO/5ip0TmyzgYw87vAn8Cn+CbwCOp/HyNNdYCmdl104a2bqcORFJzirCvvc+nNw==
   dependencies:
     "@chainsafe/as-sha256" "^0.4.1"
     "@chainsafe/persistent-merkle-tree" "^0.6.1"