diff --git a/__test__/unit/events/eventsUnique.test.ts b/__test__/unit/events/eventsUnique.test.ts
new file mode 100644
index 000000000..e88e50af3
--- /dev/null
+++ b/__test__/unit/events/eventsUnique.test.ts
@@ -0,0 +1,7 @@
+import { ONESIGNAL_EVENTS } from "../../../src/onesignal/OneSignalEvents";
+
+test('Test uniqueness of OneSignal event names', () => {
+  const events = Object.values(ONESIGNAL_EVENTS);
+  const uniqueEvents = [...new Set(events)];
+  expect(events.length).toEqual(uniqueEvents.length);
+});
diff --git a/src/onesignal/NotificationsNamespace.ts b/src/onesignal/NotificationsNamespace.ts
index dc7d6dec7..65d2e5595 100644
--- a/src/onesignal/NotificationsNamespace.ts
+++ b/src/onesignal/NotificationsNamespace.ts
@@ -6,7 +6,7 @@ import OneSignalError from "../../src/shared/errors/OneSignalError";
 import OneSignal from "./OneSignal";
 import { EventListenerBase } from "../page/userModel/EventListenerBase";
 import NotificationEventName from "../page/models/NotificationEventName";
-import { NotificationClicked } from "../../src/shared/models/Notification";
+import { NotificationClickResult, NotificationForegroundWillDisplayEvent } from "../page/models/NotificationEvent";
 
 export default class NotificationsNamespace extends EventListenerBase {
   constructor(private _permissionNative?: NotificationPermission) {
@@ -149,9 +149,9 @@ export default class NotificationsNamespace extends EventListenerBase {
   }
 
   /* Function overloads */
-  addEventListener(event: NotificationEventName.Click, listener: (obj: NotificationClicked) => void): void;
-  addEventListener(event: NotificationEventName.WillDisplay, listener: (obj: StructuredNotification) => void): void;
-  addEventListener(event: NotificationEventName.Dismiss, listener: (obj: StructuredNotification) => void): void;
+  addEventListener(event: NotificationEventName.Click, listener: (obj: NotificationClickResult) => void): void;
+  addEventListener(event: NotificationEventName.ForegroundWillDisplay, listener: (obj: NotificationForegroundWillDisplayEvent) => void): void;
+  addEventListener(event: NotificationEventName.Dismiss, listener: (obj: OSNotificationDataPayload) => void): void;
   addEventListener(event: NotificationEventName.PermissionChange,
     listener: (permission: boolean) => void): void;
   addEventListener(event: NotificationEventName.PermissionPromptDisplay, listener: () => void): void;
@@ -161,9 +161,9 @@ export default class NotificationsNamespace extends EventListenerBase {
   }
 
   /* Function overloads */
-  removeEventListener(event: NotificationEventName.Click, listener: (event: NotificationClicked) => void): void;
-  removeEventListener(event: NotificationEventName.WillDisplay, listener: (obj: StructuredNotification) => void): void;
-  removeEventListener(event: NotificationEventName.Dismiss, listener: (obj: StructuredNotification) => void): void;
+  removeEventListener(event: NotificationEventName.Click, listener: (event: NotificationClickResult) => void): void;
+  removeEventListener(event: NotificationEventName.ForegroundWillDisplay, listener: (obj: OSNotificationDataPayload) => void): void;
+  removeEventListener(event: NotificationEventName.Dismiss, listener: (obj: OSNotificationDataPayload) => void): void;
   removeEventListener(event: NotificationEventName.PermissionChange,
     listener: (permission: boolean) => void): void;
   removeEventListener(event: NotificationEventName.PermissionPromptDisplay, listener: () => void): void;
diff --git a/src/onesignal/OneSignalEvents.ts b/src/onesignal/OneSignalEvents.ts
index 1442c9be0..cce2b1a6e 100644
--- a/src/onesignal/OneSignalEvents.ts
+++ b/src/onesignal/OneSignalEvents.ts
@@ -15,7 +15,7 @@ export const ONESIGNAL_EVENTS = {
    * Occurs after the user is officially subscribed to push notifications. The service worker is fully registered
    * and activated and the user is eligible to receive push notifications at any point after this.
    */
-  SUBSCRIPTION_CHANGED: 'subscriptionChange',
+  SUBSCRIPTION_CHANGED: 'change',
   /**
    * Occurs after a POST call to OneSignal's server to send the welcome notification has completed. The actual
    * notification arrives shortly after.
@@ -24,7 +24,7 @@ export const ONESIGNAL_EVENTS = {
   /**
    * Occurs when a notification is displayed.
    */
-  NOTIFICATION_WILL_DISPLAY: 'willDisplay',
+  NOTIFICATION_WILL_DISPLAY: 'foregroundWillDisplay',
   /**
    * Occurs when a notification is dismissed by the user either clicking 'X' or clearing all notifications
    * (available in Android). This event is NOT called if the user clicks the notification's body or any of the
diff --git a/src/onesignal/PushSubscriptionNamespace.ts b/src/onesignal/PushSubscriptionNamespace.ts
index 9be86d35d..d51ec3397 100644
--- a/src/onesignal/PushSubscriptionNamespace.ts
+++ b/src/onesignal/PushSubscriptionNamespace.ts
@@ -88,11 +88,11 @@ export default class PushSubscriptionNamespace extends EventListenerBase {
     await this._enable(false);
   }
 
-  addEventListener(event: "subscriptionChange", listener: (change: SubscriptionChangeEvent) => void): void {
+  addEventListener(event: "change", listener: (change: SubscriptionChangeEvent) => void): void {
     OneSignal.emitter.on(event, listener);
   }
 
-  removeEventListener(event: "subscriptionChange", listener: (change: SubscriptionChangeEvent) => void): void {
+  removeEventListener(event: "change", listener: (change: SubscriptionChangeEvent) => void): void {
     OneSignal.emitter.off(event, listener);
   }
 
diff --git a/src/page/models/NotificationEvent.ts b/src/page/models/NotificationEvent.ts
new file mode 100644
index 000000000..ffb103ca8
--- /dev/null
+++ b/src/page/models/NotificationEvent.ts
@@ -0,0 +1,17 @@
+import { OSNotification } from "../../shared/models/OSNotification";
+
+// post-user-model
+export interface NotificationClickEvent {
+  notification: OSNotification;
+  result: NotificationClickResult;
+}
+
+export type NotificationClickResult = {
+  actionId?: string;
+  url?: string;
+}
+
+export interface NotificationForegroundWillDisplayEvent {
+  notification: OSNotification;
+  preventDefault(): void;
+}
diff --git a/src/page/models/NotificationEventName.ts b/src/page/models/NotificationEventName.ts
index ace206895..2154fb446 100644
--- a/src/page/models/NotificationEventName.ts
+++ b/src/page/models/NotificationEventName.ts
@@ -1,6 +1,6 @@
 enum NotificationEventName {
   Click = "click",
-  WillDisplay = "willDisplay",
+  ForegroundWillDisplay = "foregroundWillDisplay",
   Dismiss = "dismiss",
   PermissionChange = "permissionChange",
   PermissionPromptDisplay = "permissionPromptDisplay"
diff --git a/src/shared/helpers/OutcomesHelper.ts b/src/shared/helpers/OutcomesHelper.ts
index 7c3bf7188..0aad2ba7f 100644
--- a/src/shared/helpers/OutcomesHelper.ts
+++ b/src/shared/helpers/OutcomesHelper.ts
@@ -1,5 +1,5 @@
 import { OutcomesConfig, OutcomeAttribution, OutcomeAttributionType, SentUniqueOutcome } from '../models/Outcomes';
-import { NotificationClicked, NotificationReceived } from '../models/Notification';
+import { NotificationClicked, NotificationReceived } from '../models/OSNotification';
 import Database from "../services/Database";
 import Log from '../libraries/Log';
 import { Utils } from "../../shared/context/Utils";
diff --git a/src/shared/helpers/ServiceWorkerHelper.ts b/src/shared/helpers/ServiceWorkerHelper.ts
index 2efbebc71..fa08d683a 100755
--- a/src/shared/helpers/ServiceWorkerHelper.ts
+++ b/src/shared/helpers/ServiceWorkerHelper.ts
@@ -6,7 +6,7 @@ import { cancelableTimeout, CancelableTimeoutPromise } from '../../sw/helpers/Ca
 import Utils from "../context/Utils";
 import OutcomesHelper from "./OutcomesHelper";
 import { OSServiceWorkerFields } from "../../sw/serviceWorker/types";
-import { NotificationClicked } from "../models/Notification";
+import { NotificationClicked } from "../models/OSNotification";
 import { SessionOrigin, initializeNewSession, SessionStatus, Session } from "../models/Session";
 import OneSignalApiSW from "../api/OneSignalApiSW";
 import Path from "../models/Path";
diff --git a/src/shared/managers/ServiceWorkerManager.ts b/src/shared/managers/ServiceWorkerManager.ts
index aaf830822..7df886c65 100644
--- a/src/shared/managers/ServiceWorkerManager.ts
+++ b/src/shared/managers/ServiceWorkerManager.ts
@@ -305,7 +305,7 @@ export class ServiceWorkerManager {
           // Least likely to modify, since modifying this property changes the page's URL
           url = location.href;
         }
-        await Database.put('NotificationOpened', { url: url, data: data, timestamp: Date.now() });
+        await Database.put('NotificationOpened', { url, data, timestamp: Date.now() });
       }
       else
         await OneSignalEvent.trigger(OneSignal.EVENTS.NOTIFICATION_CLICKED, data);
diff --git a/src/shared/models/Notification.ts b/src/shared/models/OSNotification.ts
similarity index 88%
rename from src/shared/models/Notification.ts
rename to src/shared/models/OSNotification.ts
index a96b5c662..0e8f9c0f9 100755
--- a/src/shared/models/Notification.ts
+++ b/src/shared/models/OSNotification.ts
@@ -2,7 +2,7 @@ import Utils from '../context/Utils';
 import { InvalidArgumentError, InvalidArgumentReason } from '../errors/InvalidArgumentError';
 import { NotificationActionButton } from '../../page/models/NotificationActionButton';
 
-export class Notification {
+export class OSNotification {
     public id?: string;
     public title?: string;
     public body?: string;
@@ -15,7 +15,7 @@ export class Notification {
     public renotify?: true;
     public actions?: Array<NotificationActionButton>;
 
-    constructor(title: string, options?: Notification) {
+    constructor(title: string, options?: OSNotification) {
       this.title = title;
       if (options) {
         this.id = options.id;
@@ -38,7 +38,7 @@ export class Notification {
       icon = "https://onesignal.com/images/notification_logo.png",
       data = {}
     } = {}) {
-        return new Notification(title, {
+        return new OSNotification(title, {
             icon: icon,
             body: body,
             url: url,
@@ -46,11 +46,11 @@ export class Notification {
         });
     }
 
-    static createFromPushPayload(payload: any): Notification {
+    static createFromPushPayload(payload: any): OSNotification {
         if (!payload) {
             throw new InvalidArgumentError('payload', InvalidArgumentReason.Empty);
         }
-        const notification = new Notification(payload.title, {
+        const notification = new OSNotification(payload.title, {
             id: payload.custom.i,
             title: payload.title,
             body: payload.alert,
@@ -83,6 +83,7 @@ export interface NotificationReceived {
     timestamp: number;
 }
 
+// used to store click info in IndexedDB
 export interface NotificationClicked {
     notificationId: string;
     action: string;
diff --git a/src/shared/models/OSNotificationDataPayload.ts b/src/shared/models/OSNotificationDataPayload.ts
new file mode 100644
index 000000000..2077741fc
--- /dev/null
+++ b/src/shared/models/OSNotificationDataPayload.ts
@@ -0,0 +1,34 @@
+/**
+ * the data payload on the notification event notification object
+ * @see https://developer.mozilla.org/en-US/docs/Web/API/NotificationEvent
+ *
+ * @example
+ * NotificationEvent {
+ *  action: "action"
+ *  notification: Notification {
+ *    actions: (2) [{…}, {…}]
+ *    badge: ""
+ *    body: "Test Message"
+ *    data: {…}  <------ this is the OSNotificationDataPayload payload
+ *  }
+ * }
+ */
+
+ type OSNotificationDataPayload = {
+  id: string;
+  content: string;
+  heading?: string;
+  url?: string;
+  data?: object;
+  rr?: string;
+  icon?: string;
+  image?: string;
+  tag?: string;
+  badge?: string;
+  vibrate?: VibratePattern;
+  buttons?: NotificationButtonData[];
+};
+
+interface NotificationButtonData extends NotificationAction {
+  url: string;
+};
diff --git a/src/shared/models/RawNotificationPayload.ts b/src/shared/models/RawNotificationPayload.ts
new file mode 100644
index 000000000..8f9ebe1a6
--- /dev/null
+++ b/src/shared/models/RawNotificationPayload.ts
@@ -0,0 +1,18 @@
+export interface RawNotificationPayload {
+  title: string; // heading
+  alert: string; // content
+  custom: ICustomNotificationPayload;
+  icon: string;
+  image: string;
+  tag: string;
+  badge: string;
+  vibrate: string;
+  o: any[];
+}
+
+interface ICustomNotificationPayload {
+  a: any;
+  i: string;
+  u: string;
+  rr: string;
+}
diff --git a/src/shared/models/StructuredNotification.ts b/src/shared/models/StructuredNotification.ts
deleted file mode 100644
index 01d72d0e8..000000000
--- a/src/shared/models/StructuredNotification.ts
+++ /dev/null
@@ -1,21 +0,0 @@
-type StructuredNotification = {
-  id: string;
-  content: string;
-  heading?: string;
-  url?: string;
-  data?: object;
-  rr?: string;
-  icon?: string;
-  image?: string;
-  tag?: string;
-  badge?: string;
-  vibrate?: string;
-  buttons?: NotificationButtonData[];
-};
-
-type NotificationButtonData = {
-  action?: string;
-  title?: string;
-  icon?: string;
-  url?: string;
-};
diff --git a/src/shared/services/Database.ts b/src/shared/services/Database.ts
index 164dd476d..820463de4 100644
--- a/src/shared/services/Database.ts
+++ b/src/shared/services/Database.ts
@@ -3,7 +3,7 @@ import IndexedDb from "./IndexedDb";
 
 import { AppConfig } from "../models/AppConfig";
 import { AppState, ClickedNotifications } from "../models/AppState";
-import { NotificationReceived, NotificationClicked } from "../models/Notification";
+import { NotificationReceived, NotificationClicked } from "../models/OSNotification";
 import { ServiceWorkerState } from "../models/ServiceWorkerState";
 import { Subscription } from "../models/Subscription";
 import { TestEnvironmentKind } from "../models/TestEnvironmentKind";
diff --git a/src/shared/services/IndexedDb.ts b/src/shared/services/IndexedDb.ts
index a939f4080..94a7668f3 100644
--- a/src/shared/services/IndexedDb.ts
+++ b/src/shared/services/IndexedDb.ts
@@ -111,7 +111,7 @@ export default class IndexedDb {
     if (event.oldVersion < 2) {
       db.createObjectStore("Sessions", { keyPath: "sessionKey" });
       db.createObjectStore("NotificationReceived", { keyPath: "notificationId" });
-      db.createObjectStore("NotificationClicked", { keyPath: "notificationId" });
+      db.createObjectStore("NotificationClicked", { keyPath: "notification.id" });
     }
     if (event.oldVersion < 3) {
       db.createObjectStore("SentUniqueOutcome", { keyPath: "outcomeName" });
diff --git a/src/sw/serviceWorker/ServiceWorker.ts b/src/sw/serviceWorker/ServiceWorker.ts
index 863c1cb9d..d4104c1d3 100755
--- a/src/sw/serviceWorker/ServiceWorker.ts
+++ b/src/sw/serviceWorker/ServiceWorker.ts
@@ -18,7 +18,7 @@ import {
 import ServiceWorkerHelper from "../../shared/helpers/ServiceWorkerHelper";
 import { cancelableTimeout } from "../helpers/CancelableTimeout";
 import { awaitableTimeout } from "../../shared/utils/AwaitableTimeout";
-import { NotificationReceived, NotificationClicked } from "../../shared/models/Notification";
+import { NotificationReceived } from "../../shared/models/OSNotification";
 import {
   UpsertOrDeactivateSessionPayload,
   PageVisibilityResponse,
@@ -31,8 +31,10 @@ import { WorkerMessenger, WorkerMessengerMessage, WorkerMessengerCommand } from
 import { DeviceRecord } from "../../../src/shared/models/DeviceRecord";
 import { RawPushSubscription } from "../../../src/shared/models/RawPushSubscription";
 import { DeliveryPlatformKind } from "../../shared/models/DeliveryPlatformKind";
+import { NotificationClickEvent } from "../../page/models/NotificationEvent";
+import { RawNotificationPayload } from "../../shared/models/RawNotificationPayload";
 
-declare var self: ServiceWorkerGlobalScope & OSServiceWorkerFields;
+declare const self: ServiceWorkerGlobalScope & OSServiceWorkerFields;
 
 const MAX_CONFIRMED_DELIVERY_DELAY = 25;
 
@@ -100,7 +102,7 @@ export class ServiceWorker {
     self.addEventListener('activate', ServiceWorker.onServiceWorkerActivated);
     self.addEventListener('push', ServiceWorker.onPushReceived);
     self.addEventListener('notificationclose', ServiceWorker.onNotificationClosed);
-    self.addEventListener('notificationclick', event => event.waitUntil(ServiceWorker.onNotificationClicked(event)));
+    self.addEventListener('notificationclick', (event: NotificationEvent) => event.waitUntil(ServiceWorker.onNotificationClicked(event)));
     self.addEventListener('pushsubscriptionchange', (event: Event) => {
       (event as FetchEvent).waitUntil(ServiceWorker.onPushSubscriptionChange(event as unknown as SubscriptionChangeEvent));
     });
@@ -245,13 +247,13 @@ export class ServiceWorker {
 
     event.waitUntil(
         ServiceWorker.parseOrFetchNotifications(event)
-            .then(async (notifications: any) => {
+            .then(async (rawNotificationsArray: RawNotificationPayload[]) => {
               //Display push notifications in the order we received them
               const notificationEventPromiseFns = [];
               const notificationReceivedPromises: Promise<void>[] = [];
               const appId = await ServiceWorker.getAppId();
 
-              for (const rawNotification of notifications) {
+              for (const rawNotification of rawNotificationsArray) {
                 Log.debug('Raw Notification from OneSignal:', rawNotification);
                 const notification = ServiceWorker.buildStructuredNotificationObject(rawNotification);
 
@@ -266,7 +268,7 @@ export class ServiceWorker {
                 // Probably should have it's own error handling but not blocking the rest of the execution?
 
                 // Never nest the following line in a callback from the point of entering from retrieveNotifications
-                notificationEventPromiseFns.push((async notif => {
+                notificationEventPromiseFns.push((async (notif: OSNotificationDataPayload) => {
                   await ServiceWorker.workerMessenger.broadcast(WorkerMessengerCommand.NotificationWillDisplay, notif).catch(e => Log.error(e));
                   ServiceWorker.executeWebhooks('notification.willDisplay', notif);
 
@@ -526,8 +528,8 @@ export class ServiceWorker {
    * Constructed in onPushReceived, and passed along to other event handlers.
    * @param rawNotification The raw notification JSON returned from OneSignal's server.
    */
-  static buildStructuredNotificationObject(rawNotification) {
-    const notification: StructuredNotification = {
+  static buildStructuredNotificationObject(rawNotification: RawNotificationPayload): OSNotificationDataPayload {
+    const notification: OSNotificationDataPayload = {
       id: rawNotification.custom.i,
       heading: rawNotification.title,
       content: rawNotification.alert,
@@ -538,7 +540,7 @@ export class ServiceWorker {
       image: rawNotification.image,
       tag: rawNotification.tag,
       badge: rawNotification.badge,
-      vibrate: rawNotification.vibrate
+      vibrate: Number(rawNotification.vibrate)
     };
 
     // Add action buttons
@@ -553,7 +555,7 @@ export class ServiceWorker {
                                   });
       }
     }
-    return Utils.trimUndefined(notification);
+    return Utils.trimUndefined(notification) as OSNotificationDataPayload;
   }
 
   /**
@@ -612,13 +614,13 @@ export class ServiceWorker {
    * Any event needing to display a notification calls this so that all the display options can be centralized here.
    * @param notification A structured notification object.
    */
-  static async displayNotification(notification, overrides?) {
+  static async displayNotification(notification: OSNotificationDataPayload, overrides?: object) {
     Log.debug(`Called %cdisplayNotification(${JSON.stringify(notification, null, 4)}):`, Utils.getConsoleStyle('code'), notification);
 
     // Use the default title if one isn't provided
-    const defaultTitle = await ServiceWorker._getTitle();
+    const defaultTitle: string = await ServiceWorker._getTitle();
     // Use the default icon if one isn't provided
-    const defaultIcon = await Database.get('Options', 'defaultIcon');
+    const defaultIcon: string = await Database.get('Options', 'defaultIcon');
     // Get option of whether we should leave notification displaying indefinitely
     const persistNotification = await Database.get('Options', 'persistNotification');
     // Get app ID for tag value
@@ -632,8 +634,9 @@ export class ServiceWorker {
     extra.persistNotification = persistNotification !== false;
 
     // Allow overriding some values
-    if (!overrides)
+    if (!overrides) {
       overrides = {};
+    }
     notification = { ...notification, ...overrides };
 
     ServiceWorker.ensureNotificationResourcesHttps(notification);
@@ -769,18 +772,13 @@ export class ServiceWorker {
    * Occurs when the notification's body or action buttons are clicked. Does not occur if the notification is
    * dismissed by clicking the 'X' icon. See the notification close event for the dismissal event.
    */
-  static async onNotificationClicked(event: NotificationEventInit) {
+  static async onNotificationClicked(event: NotificationEvent) {
     Log.debug(`Called %conNotificationClicked(${JSON.stringify(event, null, 4)}):`, Utils.getConsoleStyle('code'), event);
 
     // Close the notification first here, before we do anything that might fail
     event.notification.close();
 
-    const { data } = event.notification;
-
-    // Chrome 48+: Get the action button that was clicked
-    if (event.action) {
-      data.action = event.action;
-    }
+    const data = event.notification.data as OSNotificationDataPayload;
 
     let notificationClickHandlerMatch = 'exact';
     let notificationClickHandlerAction = 'navigate';
@@ -798,14 +796,15 @@ export class ServiceWorker {
     const appId = await ServiceWorker.getAppId();
     const deviceType = DeviceRecord.prototype.getDeliveryPlatform();
 
-    const notificationClicked: NotificationClicked = {
-      notificationId: data.id,
-      action: data.action,
-      appId,
-      url: launchUrl,
-      timestamp: new Date().getTime(),
-    };
-    Log.info("NotificationClicked", notificationClicked);
+    const notificationClickEvent: NotificationClickEvent = {
+      notification: data,
+      result: {
+        url: data.url,
+        actionId: event.action, // get action id directly from event
+      }
+    }
+
+    Log.info("NotificationClicked", notificationClickEvent);
     const saveNotificationClickedPromise = (async notificationClicked => {
       try {
         const existingSession = await Database.getCurrentSession();
@@ -817,13 +816,13 @@ export class ServiceWorker {
         // upgrade existing session to be directly attributed to the notif
         // if it results in re-focusing the site
         if (existingSession) {
-          existingSession.notificationId = notificationClicked.notificationId;
+          existingSession.notificationId = notificationClicked.notification.id as string | null;
           await Database.upsertSession(existingSession);
         }
       } catch(e) {
         Log.error("Failed to save clicked notification.", e);
       }
-    })(notificationClicked);
+    })(notificationClickEvent);
 
     // Start making REST API requests BEFORE self.clients.openWindow is called.
     // It will cause the service worker to stop on Chrome for Android when site is added to the home screen.
@@ -867,7 +866,7 @@ export class ServiceWorker {
         if ((client['isSubdomainIframe'] && clientUrl === launchUrl) ||
             (!client['isSubdomainIframe'] && client.url === launchUrl) ||
           (notificationClickHandlerAction === 'focus' && clientOrigin === launchOrigin)) {
-          ServiceWorker.workerMessenger.unicast(WorkerMessengerCommand.NotificationClicked, data, client);
+          ServiceWorker.workerMessenger.unicast(WorkerMessengerCommand.NotificationClicked, notificationClickEvent, client);
             try {
               if (client instanceof WindowClient)
                 await client.focus();
@@ -1086,9 +1085,9 @@ export class ServiceWorker {
   /**
    * Returns a promise that is fulfilled with either the default title from the database (first priority) or the page title from the database (alternate result).
    */
-  static _getTitle() {
+  static _getTitle(): Promise<string> {
     return new Promise(resolve => {
-      Promise.all([Database.get('Options', 'defaultTitle'), Database.get('Options', 'pageTitle')])
+      Promise.all([Database.get<string>('Options', 'defaultTitle'), Database.get<string>('Options', 'pageTitle')])
         .then(([defaultTitle, pageTitle]) => {
           if (defaultTitle !== null) {
             resolve(defaultTitle);
@@ -1109,7 +1108,7 @@ export class ServiceWorker {
    * @returns An array of notifications. The new web push protocol will only ever contain one notification, however
    * an array is returned for backwards compatibility with the rest of the service worker plumbing.
      */
-  static parseOrFetchNotifications(event) {
+  static parseOrFetchNotifications(event: PushEvent): Promise<RawNotificationPayload[]> {
     if (!event || !event.data) {
       return Promise.reject("Missing event.data on push payload!");
     }
@@ -1117,7 +1116,8 @@ export class ServiceWorker {
     const isValidPayload = ServiceWorker.isValidPushPayload(event.data);
     if (isValidPayload) {
       Log.debug("Received a valid encrypted push payload.");
-      return Promise.resolve([event.data.json()]);
+      const payload: RawNotificationPayload = event.data.json();
+      return Promise.resolve([payload]);
     }
 
     /*
@@ -1132,9 +1132,9 @@ export class ServiceWorker {
    * Otherwise returns false.
    * @param rawData The raw PushMessageData from the push event's event.data, not already parsed to JSON.
    */
-  static isValidPushPayload(rawData) {
+  static isValidPushPayload(rawData: PushMessageData) {
     try {
-      const payload = rawData.json();
+      const payload: RawNotificationPayload = rawData.json();
       if (payload &&
           payload.custom &&
           payload.custom.i &&
diff --git a/test/support/tester/OutcomeTestHelper.ts b/test/support/tester/OutcomeTestHelper.ts
index 4258974ac..dc6a30d87 100644
--- a/test/support/tester/OutcomeTestHelper.ts
+++ b/test/support/tester/OutcomeTestHelper.ts
@@ -1,7 +1,7 @@
 import Random from '../../support/tester/Random';
 import Database from '../../../src/shared/services/Database';
 import { initializeNewSession, Session } from '../../../src/shared/models/Session';
-import { NotificationClicked, NotificationReceived } from '../../../src/shared/models/Notification';
+import { NotificationClicked, NotificationReceived } from '../../../src/shared/models/OSNotification';
 
 const TEN_MINUTES_MS = 10 * 60 * 1000;