diff --git a/packages/transactions/src.ts/index.ts b/packages/transactions/src.ts/index.ts
index f3e3556512..f5c433a9c4 100644
--- a/packages/transactions/src.ts/index.ts
+++ b/packages/transactions/src.ts/index.ts
@@ -252,7 +252,12 @@ function _serialize(transaction: UnsignedTransaction, signature?: SignatureLike)
 
 export function serialize(transaction: UnsignedTransaction, signature?: SignatureLike): string {
     // Legacy and EIP-155 Transactions
-    if (transaction.type == null) { return _serialize(transaction, signature); }
+    if (transaction.type == null) {
+        if (transaction.accessList != null) {
+            logger.throwArgumentError("untyped transactions do not support accessList; include type: 1", "transaction", transaction);
+        }
+        return _serialize(transaction, signature);
+    }
 
     // Typed Transactions (EIP-2718)
     switch (transaction.type) {