diff --git a/packages/message-hash/src/index.spec.ts b/packages/message-hash/src/index.spec.ts
index d8045be6b9..62846c6415 100644
--- a/packages/message-hash/src/index.spec.ts
+++ b/packages/message-hash/src/index.spec.ts
@@ -95,7 +95,7 @@ describe("RFC Test Vectors", () => {
 
   it("Waku message hash computation (message is IDecodedMessage)", () => {
     const expectedHash =
-      "bd81b27902ad51f49e8f73ff8db4a96994040c9421da88b7ee8ba07bd39070b2";
+      "3f11bc950dce0e3ffdcf205ae6414c01130bb5d9f20644869bff80407fa52c8f";
     const pubsubTopic = "/waku/2/default-waku/proto";
     const message: IDecodedMessage = {
       payload: new Uint8Array(),
diff --git a/packages/message-hash/src/index.ts b/packages/message-hash/src/index.ts
index 7cfd57a0dc..825143ca95 100644
--- a/packages/message-hash/src/index.ts
+++ b/packages/message-hash/src/index.ts
@@ -40,7 +40,15 @@ function tryConvertTimestampToBytes(
     return;
   }
 
-  return numberToBytes(timestamp.valueOf());
+  let bigIntTimestamp: bigint;
+
+  if (typeof timestamp === "bigint") {
+    bigIntTimestamp = timestamp;
+  } else {
+    bigIntTimestamp = BigInt(timestamp.valueOf()) * 1000000n;
+  }
+
+  return numberToBytes(bigIntTimestamp);
 }
 
 export function messageHashStr(