diff --git a/typescript/sdk/src/core/HyperlaneCore.ts b/typescript/sdk/src/core/HyperlaneCore.ts
index 4c5c794d3e..8b1425d102 100644
--- a/typescript/sdk/src/core/HyperlaneCore.ts
+++ b/typescript/sdk/src/core/HyperlaneCore.ts
@@ -42,6 +42,10 @@ import { CoreFactories, coreFactories } from './contracts.js';
 import { DispatchEvent } from './events.js';
 import { DispatchedMessage } from './types.js';
 
+// If no metadata is provided, ensure we provide a default of 0x0001.
+// We set to 0x0001 instead of 0x0 to ensure it does not break on zksync.
+const DEFAULT_METADATA = '0x0001';
+
 export class HyperlaneCore extends HyperlaneApp<CoreFactories> {
   static fromAddressesMap(
     addressesMap: HyperlaneAddressesMap<any>,
@@ -94,7 +98,7 @@ export class HyperlaneCore extends HyperlaneApp<CoreFactories> {
       destinationId,
       recipient,
       body,
-      metadata || '0x0001',
+      metadata || DEFAULT_METADATA,
       hook || ethers.constants.AddressZero,
     );
   };
@@ -159,7 +163,7 @@ export class HyperlaneCore extends HyperlaneApp<CoreFactories> {
       destinationDomain,
       recipientBytes32,
       body,
-      metadata || '0x0001',
+      metadata || DEFAULT_METADATA,
       hook || ethers.constants.AddressZero,
     ] as const;