diff --git a/packages/rpc-subscriptions-api/src/slots-updates-notifications.ts b/packages/rpc-subscriptions-api/src/slots-updates-notifications.ts
index e4e3f7e78740..082008d06b0e 100644
--- a/packages/rpc-subscriptions-api/src/slots-updates-notifications.ts
+++ b/packages/rpc-subscriptions-api/src/slots-updates-notifications.ts
@@ -25,6 +25,7 @@ type SlotsUpdatesNotificationsApiNotificationFrozen = Readonly<{
         numSuccessfulTransactions: bigint;
         numTransactionEntries: bigint;
     }>;
+    hash?: string;
     type: 'frozen';
 }> &
     SlotsUpdatesNotificationsApiNotificationBase;