diff --git a/packages/core/base/src/types.ts b/packages/core/base/src/types.ts
index 65247a098..24aa5b327 100644
--- a/packages/core/base/src/types.ts
+++ b/packages/core/base/src/types.ts
@@ -12,3 +12,9 @@ export enum WalletAdapterNetwork {
 
 export type TransactionOrVersionedTransaction<SupportedTransactionVersions extends Set<TransactionVersion> | null> =
     SupportedTransactionVersions extends null ? Transaction : Transaction | VersionedTransaction;
+
+export function isVersionedTransaction(
+    transaction: Transaction | VersionedTransaction
+): transaction is VersionedTransaction {
+    return 'message' in transaction;
+}