diff --git a/src/index.ts b/src/index.ts
index 75b9d20..d1a1d14 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -30,11 +30,13 @@ async function main() {
 
     const appleNotificationSender = new AppleNotificationSender(false);
     notificationRepository = new InMemoryNotificationRepository();
+
     notificationService = new ETANotificationScheduler(
       shuttleRepository,
       notificationRepository,
       appleNotificationSender
     );
+    notificationService.startListeningForUpdates();
   } else {
     const repositoryDataUpdater = new TimedApiBasedShuttleRepositoryLoader(
       shuttleRepository,
@@ -46,6 +48,7 @@ async function main() {
       shuttleRepository,
       notificationRepository
     );
+    notificationService.startListeningForUpdates();
   }
 
   const { url } = await startStandaloneServer(server, {
diff --git a/test/notifications/schedulers/ETANotificationSchedulerTests.test.ts b/test/notifications/schedulers/ETANotificationSchedulerTests.test.ts
index cadee33..974774d 100644
--- a/test/notifications/schedulers/ETANotificationSchedulerTests.test.ts
+++ b/test/notifications/schedulers/ETANotificationSchedulerTests.test.ts
@@ -1,7 +1,6 @@
 import { beforeEach, describe, expect, it, jest } from "@jest/globals";
 import { ETANotificationScheduler } from "../../../src/notifications/schedulers/ETANotificationScheduler";
 import { UnoptimizedInMemoryShuttleRepository } from "../../../src/repositories/UnoptimizedInMemoryShuttleRepository";
-import http2 from "http2";
 import { IEta, IShuttle, IStop } from "../../../src/entities/entities";
 import { addMockShuttleToRepository, addMockStopToRepository } from "../../testHelpers/repositorySetupHelpers";
 import { AppleNotificationSender } from "../../../src/notifications/senders/AppleNotificationSender";
@@ -17,23 +16,6 @@ function mockNotificationSenderMethods(shouldSimulateNotificationSend: boolean)
   MockAppleNotificationSender.prototype.sendNotificationImmediately = jest.fn(async () => shouldSimulateNotificationSend);
 }
 
-/**
- * Wait for a condition to become true until the timeout
- * is hit.
- * @param condition
- * @param timeoutMilliseconds
- * @param intervalMilliseconds
- */
-async function waitForCondition(condition: () => boolean, timeoutMilliseconds = 5000, intervalMilliseconds = 500) {
-  const startTime = Date.now();
-  while (!condition()) {
-    if (Date.now() - startTime > timeoutMilliseconds) {
-      throw new Error("Timeout waiting for condition");
-    }
-    await new Promise((resolve) => setTimeout(resolve, intervalMilliseconds));
-  }
-}
-
 /**
  * Wait for a specified number of milliseconds.
  * @param ms
@@ -60,6 +42,7 @@ describe("ETANotificationScheduler", () => {
       notificationRepository,
       appleNotificationSender
     );
+    notificationService.startListeningForUpdates();
   });
 
   function generateNotificationDataAndEta(shuttle: IShuttle, stop: IStop) {
@@ -97,9 +80,8 @@ describe("ETANotificationScheduler", () => {
       await shuttleRepository.addOrUpdateEta(eta);
 
       // Assert
-      // Because repository publisher calls subscriber without await
-      // wait for the change to occur first
-      await waitForCondition(() => !notificationRepository.isNotificationScheduled(notificationData1));
+      // Wait for the callback to actually be called
+      await waitForMilliseconds(1000);
 
       const isFirstNotificationScheduled = await notificationRepository.isNotificationScheduled(notificationData1);
       const isSecondNotificationScheduled = await notificationRepository.isNotificationScheduled(notificationData2);
@@ -132,12 +114,18 @@ describe("ETANotificationScheduler", () => {
       const stop = await addMockStopToRepository(shuttleRepository, "1");
       const { eta, notificationData1 } = generateNotificationDataAndEta(shuttle, stop)
 
+      // replace the old notification scheduler with a new one
+      // detach the old callback method from the shuttle repo
+      notificationService.stopListeningForUpdates();
+
       mockNotificationSenderMethods(false);
+      const updatedNotificationSender = new MockAppleNotificationSender(false);
       notificationService = new ETANotificationScheduler(
         shuttleRepository,
-        new InMemoryNotificationRepository(),
-        new MockAppleNotificationSender(),
-      )
+        notificationRepository,
+        updatedNotificationSender
+      );
+      notificationService.startListeningForUpdates();
 
       // Act
       await notificationRepository.addOrUpdateNotification(notificationData1);