diff --git a/packages/notification-services-controller/CHANGELOG.md b/packages/notification-services-controller/CHANGELOG.md
index 5cd7324ed8..91924e3c7c 100644
--- a/packages/notification-services-controller/CHANGELOG.md
+++ b/packages/notification-services-controller/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- Update `isOnChainRawNotification` to detect on-chain notifications using the v4 `notification_type` discriminator instead of legacy payload field checks, fixing web push notification handling after the v4 API migration ([#9407](https://github.com/MetaMask/core/pull/9407))
+
 ## [25.0.0]
 
 ### Added
diff --git a/packages/notification-services-controller/src/shared/is-onchain-notification.ts b/packages/notification-services-controller/src/shared/is-onchain-notification.ts
index 50107c5d30..a251882885 100644
--- a/packages/notification-services-controller/src/shared/is-onchain-notification.ts
+++ b/packages/notification-services-controller/src/shared/is-onchain-notification.ts
@@ -1,21 +1,17 @@
-import type { OnChainRawNotification } from '../NotificationServicesController';
+import type {
+  UnprocessedRawNotification,
+  OnChainNotification,
+} from '../NotificationServicesController/types/notification-api';
+import { isOnChainNotification } from './notification-api-type-guards';
 
 /**
- * Checks if the given value is an OnChainRawNotification object.
+ * Checks if the given value is an on-chain notification using the v4 `notification_type` discriminator.
  *
  * @param notification - The value to check.
- * @returns True if the value is an OnChainRawNotification object, false otherwise.
+ * @returns True if the value is an on-chain notification, false otherwise.
  */
 export function isOnChainRawNotification(
   notification: unknown,
-): notification is OnChainRawNotification {
-  const assumed = notification as OnChainRawNotification;
-
-  // We don't have a validation/parsing library to check all possible types of an on chain notification
-  // It is safe enough just to check "some" fields, and catch any errors down the line if the shape is bad.
-  const isValidEnoughToBeOnChainNotification = [
-    assumed?.id,
-    assumed?.payload?.data,
-  ].every((field) => field !== undefined);
-  return isValidEnoughToBeOnChainNotification;
+): notification is OnChainNotification {
+  return isOnChainNotification(notification as UnprocessedRawNotification);
 }