diff --git a/eslint-suppressions.json b/eslint-suppressions.json
index 780f3e9a216..23e66aa2ad3 100644
--- a/eslint-suppressions.json
+++ b/eslint-suppressions.json
@@ -1915,21 +1915,6 @@
       "count": 1
     }
   },
-  "packages/notification-services-controller/src/NotificationServicesPushController/mocks/mockResponse.ts": {
-    "@typescript-eslint/explicit-function-return-type": {
-      "count": 3
-    }
-  },
-  "packages/notification-services-controller/src/NotificationServicesPushController/services/endpoints.ts": {
-    "@typescript-eslint/explicit-function-return-type": {
-      "count": 2
-    }
-  },
-  "packages/notification-services-controller/src/NotificationServicesPushController/services/services.test.ts": {
-    "@typescript-eslint/explicit-function-return-type": {
-      "count": 4
-    }
-  },
   "packages/notification-services-controller/src/NotificationServicesPushController/services/services.ts": {
     "@typescript-eslint/naming-convention": {
       "count": 1
diff --git a/packages/notification-services-controller/src/NotificationServicesPushController/mocks/mockResponse.ts b/packages/notification-services-controller/src/NotificationServicesPushController/mocks/mockResponse.ts
index 3395c3de88b..9b83fca11b4 100644
--- a/packages/notification-services-controller/src/NotificationServicesPushController/mocks/mockResponse.ts
+++ b/packages/notification-services-controller/src/NotificationServicesPushController/mocks/mockResponse.ts
@@ -8,7 +8,7 @@ type MockResponse = {
 
 export const MOCK_REG_TOKEN = 'REG_TOKEN';
 
-export const getMockUpdatePushNotificationLinksResponse = () => {
+export const getMockUpdatePushNotificationLinksResponse = (): MockResponse => {
   return {
     url: REGISTRATION_TOKENS_ENDPOINT(),
     requestMethod: 'POST',
@@ -27,7 +27,7 @@ export const MOCK_FCM_RESPONSE = {
   },
 };
 
-export const getMockCreateFCMRegistrationTokenResponse = () => {
+export const getMockCreateFCMRegistrationTokenResponse = (): MockResponse => {
   return {
     url: /^https:\/\/fcmregistrations\.googleapis\.com\/v1\/projects\/.*$/u,
     requestMethod: 'POST',
@@ -35,7 +35,7 @@ export const getMockCreateFCMRegistrationTokenResponse = () => {
   } satisfies MockResponse;
 };
 
-export const getMockDeleteFCMRegistrationTokenResponse = () => {
+export const getMockDeleteFCMRegistrationTokenResponse = (): MockResponse => {
   return {
     url: /^https:\/\/fcmregistrations\.googleapis\.com\/v1\/projects\/.*$/u,
     requestMethod: 'POST',
diff --git a/packages/notification-services-controller/src/NotificationServicesPushController/services/endpoints.ts b/packages/notification-services-controller/src/NotificationServicesPushController/services/endpoints.ts
index 34a1b7c3c8c..d5d432c2720 100644
--- a/packages/notification-services-controller/src/NotificationServicesPushController/services/endpoints.ts
+++ b/packages/notification-services-controller/src/NotificationServicesPushController/services/endpoints.ts
@@ -6,8 +6,8 @@ const PUSH_API_ENV = {
   prd: 'https://push.api.cx.metamask.io',
 } satisfies Record<ENV, string>;
 
-export const PUSH_API = (env: ENV = 'prd') =>
+export const PUSH_API = (env: ENV = 'prd'): string =>
   PUSH_API_ENV[env] ?? PUSH_API_ENV.prd;
 
-export const REGISTRATION_TOKENS_ENDPOINT = (env: ENV = 'prd') =>
+export const REGISTRATION_TOKENS_ENDPOINT = (env: ENV = 'prd'): string =>
   `${PUSH_API(env)}/api/v2/token`;
diff --git a/packages/notification-services-controller/src/NotificationServicesPushController/services/services.test.ts b/packages/notification-services-controller/src/NotificationServicesPushController/services/services.test.ts
index 4fd8089a195..69c3de3a2b5 100644
--- a/packages/notification-services-controller/src/NotificationServicesPushController/services/services.test.ts
+++ b/packages/notification-services-controller/src/NotificationServicesPushController/services/services.test.ts
@@ -9,7 +9,7 @@ import { mockEndpointUpdatePushNotificationLinks } from '../__fixtures__/mockSer
 import type { PushNotificationEnv } from '../types/firebase';
 
 // Testing util to clean up verbose logs when testing errors
-const mockErrorLog = () =>
+const mockErrorLog = (): jest.SpyInstance =>
   jest.spyOn(log, 'error').mockImplementation(jest.fn());
 
 const MOCK_REG_TOKEN = 'REG_TOKEN';
@@ -19,7 +19,7 @@ const MOCK_JWT = 'MOCK_JWT';
 
 describe('NotificationServicesPushController Services', () => {
   describe('updateLinksAPI', () => {
-    const act = async () =>
+    const act = async (): Promise<boolean> =>
       await updateLinksAPI({
         bearerToken: MOCK_JWT,
         addresses: MOCK_ADDRESSES,
@@ -54,6 +54,8 @@ describe('NotificationServicesPushController Services', () => {
   });
 
   describe('activatePushNotifications', () => {
+    // Internal testing utility - return type is inferred
+    // eslint-disable-next-line @typescript-eslint/explicit-function-return-type
     const arrangeMocks = (override?: { mockPut?: { status: number } }) => {
       const params = {
         bearerToken: MOCK_JWT,
@@ -124,6 +126,8 @@ describe('NotificationServicesPushController Services', () => {
   });
 
   describe('deactivatePushNotifications', () => {
+    // Internal testing utility - return type is inferred
+    // eslint-disable-next-line @typescript-eslint/explicit-function-return-type
     const arrangeMocks = () => {
       const params = {
         regToken: MOCK_REG_TOKEN,