diff --git a/configs/.eslintrc.ts b/configs/.eslintrc.ts
index bc652f2d..e05fc416 100644
--- a/configs/.eslintrc.ts
+++ b/configs/.eslintrc.ts
@@ -39,6 +39,7 @@ const config: ESLint.ConfigData = {
         count: 1,
       },
     ],
+    'require-await': 'error',
     '@typescript-eslint/no-unused-vars': [
       'error',
       {
diff --git a/src/background/RemotePontoon.ts b/src/background/RemotePontoon.ts
index 4c21f1a9..2379db52 100644
--- a/src/background/RemotePontoon.ts
+++ b/src/background/RemotePontoon.ts
@@ -68,7 +68,7 @@ export function listenToMessagesFromClients() {
   listenToMessagesExclusively(
     BackgroundClientMessageType.UPDATE_TEAMS_LIST,
     async () => {
-      return updateTeamsList();
+      return await updateTeamsList();
     },
   );
   listenToMessagesExclusively(
@@ -82,7 +82,7 @@ export function listenToMessagesFromClients() {
   listenToMessagesExclusively(
     BackgroundClientMessageType.GET_TEAM_FROM_PONTOON,
     async () => {
-      return getUsersTeamFromPontoon();
+      return await getUsersTeamFromPontoon();
     },
   );
 }
diff --git a/src/background/backgroundClient.ts b/src/background/backgroundClient.ts
index de325f29..36bd9b4e 100644
--- a/src/background/backgroundClient.ts
+++ b/src/background/backgroundClient.ts
@@ -17,7 +17,7 @@ async function getTeam(): Promise<{ code: string }> {
 }
 
 async function getPontoonBaseUrl(): Promise<string> {
-  return getOneOption('pontoon_base_url');
+  return await getOneOption('pontoon_base_url');
 }
 
 export async function getNotificationsUrl(): Promise<string> {
@@ -87,7 +87,7 @@ export async function reportTranslatedTextToBugzilla(text: string) {
 export async function notificationBellIconScriptLoaded(): Promise<{
   type: BackgroundClientMessageType;
 }> {
-  return browser.runtime.sendMessage({
+  return await browser.runtime.sendMessage({
     type: BackgroundClientMessageType.NOTIFICATIONS_BELL_SCRIPT_LOADED,
   });
 }
diff --git a/src/background/httpClients.ts b/src/background/httpClients.ts
index 8f8b5e83..fe067ba5 100644
--- a/src/background/httpClients.ts
+++ b/src/background/httpClients.ts
@@ -143,7 +143,7 @@ export const pontoonHttpClient = new PontoonHttpClient();
 
 export const httpClient = {
   fetch: async (url: string): Promise<Response> => {
-    return fetch(url, { credentials: 'omit' });
+    return await fetch(url, { credentials: 'omit' });
   },
 };
 
diff --git a/src/commons/webExtensionsApi/index.ts b/src/commons/webExtensionsApi/index.ts
index ece7db0c..f26453f6 100644
--- a/src/commons/webExtensionsApi/index.ts
+++ b/src/commons/webExtensionsApi/index.ts
@@ -108,13 +108,13 @@ export function listenToStorageChange<K extends keyof StorageContent>(
 }
 
 export async function saveToStorage(toSave: Partial<StorageContent>) {
-  return browser.storage.local.set(toSave);
+  return await browser.storage.local.set(toSave);
 }
 
 export async function deleteFromStorage<K extends keyof StorageContent>(
   ...storageKeys: K[]
 ) {
-  return browser.storage.local.remove(storageKeys);
+  return await browser.storage.local.remove(storageKeys);
 }
 
 export async function createNotification(
@@ -132,7 +132,7 @@ export async function createNotification(
 }
 
 export async function closeNotification(notificationId: string) {
-  return browser.notifications.clear(notificationId);
+  return await browser.notifications.clear(notificationId);
 }
 
 export function createContextMenu(
@@ -142,7 +142,7 @@ export function createContextMenu(
 }
 
 export async function removeContextMenu(menuItemId: number | string) {
-  return browser.contextMenus.remove(menuItemId);
+  return await browser.contextMenus.remove(menuItemId);
 }
 
 export function browserFamily(): BrowserFamily {
@@ -154,26 +154,26 @@ export function browserFamily(): BrowserFamily {
 }
 
 export async function openNewTab(url: string) {
-  return browser.tabs.create({ url });
+  return await browser.tabs.create({ url });
 }
 
 export async function getAllTabs() {
-  return browser.tabs.query({});
+  return await browser.tabs.query({});
 }
 
 export async function getTabsMatching(...patterns: string[]) {
-  return browser.tabs.query({ url: patterns });
+  return await browser.tabs.query({ url: patterns });
 }
 
 export async function getTabsWithBaseUrl(baseUrl: string) {
-  return getTabsMatching(`${baseUrl}/*`);
+  return await getTabsMatching(`${baseUrl}/*`);
 }
 
 export async function getActiveTab(): Promise<Tabs.Tab> {
   return (await browser.tabs.query({ currentWindow: true, active: true }))[0];
 }
 
-export async function listenToTabsCompletedLoading(
+export function listenToTabsCompletedLoading(
   listener: (tab: Tabs.Tab & { id: number }) => void,
 ) {
   browser.tabs.onUpdated.addListener((tabId, changeInfo, tab) => {
@@ -188,23 +188,25 @@ export function getResourceUrl(path: string) {
 }
 
 export async function openOptions() {
-  return browser.runtime.openOptionsPage();
+  return await browser.runtime.openOptionsPage();
 }
 
 export async function openIntro() {
-  return openNewTab(browser.runtime.getURL('frontend/intro.html'));
+  return await openNewTab(browser.runtime.getURL('frontend/intro.html'));
 }
 
 export async function openPrivacyPolicy() {
-  return openNewTab(browser.runtime.getURL('frontend/privacy-policy.html'));
+  return await openNewTab(
+    browser.runtime.getURL('frontend/privacy-policy.html'),
+  );
 }
 
 export async function openSnakeGame() {
-  return openNewTab(browser.runtime.getURL('frontend/snake-game.html'));
+  return await openNewTab(browser.runtime.getURL('frontend/snake-game.html'));
 }
 
 export async function openToolbarButtonPopup() {
-  return browser.browserAction.openPopup();
+  return await browser.browserAction.openPopup();
 }
 
 export function supportsAddressBar(): boolean {
@@ -241,18 +243,20 @@ export function supportsContainers(): boolean {
 
 export async function getAllContainers() {
   if (supportsContainers()) {
-    return browser.contextualIdentities.query({});
+    return await browser.contextualIdentities.query({});
   } else {
     return [];
   }
 }
 
 export async function requestPermissionForPontoon(pontoonBaseUrl: string) {
-  return browser.permissions.request({ origins: [`${pontoonBaseUrl}/*`] });
+  return await browser.permissions.request({
+    origins: [`${pontoonBaseUrl}/*`],
+  });
 }
 
 export async function registerScriptForBaseUrl(baseUrl: string, file: string) {
-  return browser.contentScripts.register({
+  return await browser.contentScripts.register({
     js: [{ file }],
     matches: [`${baseUrl}/*`],
     runAt: 'document_end', // Corresponds to interactive. The DOM has finished loading, but resources such as scripts and images may still be loading.
@@ -260,7 +264,7 @@ export async function registerScriptForBaseUrl(baseUrl: string, file: string) {
 }
 
 export async function executeScript(tabId: number, file: string) {
-  return browser.tabs.executeScript(tabId, { file });
+  return await browser.tabs.executeScript(tabId, { file });
 }
 
 export function callWithInterval(
diff --git a/src/commons/webExtensionsApi/spec.ts b/src/commons/webExtensionsApi/spec.ts
index b5cb47c2..cf02ea38 100644
--- a/src/commons/webExtensionsApi/spec.ts
+++ b/src/commons/webExtensionsApi/spec.ts
@@ -284,7 +284,7 @@ describe('webExtensionsApi', () => {
       .expect(42, { file: 'foo/bar.js' })
       .andResolve([]);
 
-    executeScript(42, 'foo/bar.js');
+    await executeScript(42, 'foo/bar.js');
   });
 
   it('callWithInterval', () => {
diff --git a/src/content-scripts/pontoon-addon-promotion/content-script.ts b/src/content-scripts/pontoon-addon-promotion/content-script.ts
index 152419e3..47dd64ec 100644
--- a/src/content-scripts/pontoon-addon-promotion/content-script.ts
+++ b/src/content-scripts/pontoon-addon-promotion/content-script.ts
@@ -8,7 +8,7 @@ function injectScript(src: string) {
   document.head.prepend(script);
 }
 
-async function postMessage(): Promise<void> {
+function postMessage() {
   window.postMessage(
     {
       _type: 'PontoonAddonInfo',
diff --git a/src/frontend/index.spec.ts b/src/frontend/index.spec.ts
index 20e86ae5..f7ff1fc7 100644
--- a/src/frontend/index.spec.ts
+++ b/src/frontend/index.spec.ts
@@ -50,7 +50,7 @@ describe('address bar', () => {
     const root = prepareRoot('address-bar-root');
 
     await act(async () => {
-      await index();
+      index();
       await flushPromises();
     });
 
@@ -63,7 +63,7 @@ describe('intro', () => {
     const root = prepareRoot('intro-root');
 
     await act(async () => {
-      await index();
+      index();
       await flushPromises();
     });
 
@@ -76,7 +76,7 @@ describe('options', () => {
     const root = prepareRoot('options-root');
 
     await act(async () => {
-      await index();
+      index();
       await flushPromises();
     });
 
@@ -89,7 +89,7 @@ describe('privacy policy', () => {
     const root = prepareRoot('privacy-policy-root');
 
     await act(async () => {
-      await index();
+      index();
       await flushPromises();
     });
 
@@ -102,7 +102,7 @@ describe('snake game', () => {
     const root = prepareRoot('snake-game-root');
 
     await act(async () => {
-      await index();
+      index();
       await flushPromises();
     });
 
@@ -130,7 +130,7 @@ describe('toolbar button', () => {
     const root = prepareRoot('toolbar-button-root');
 
     await act(async () => {
-      await index();
+      index();
       await flushPromises();
     });
 
diff --git a/src/frontend/index.tsx b/src/frontend/index.tsx
index abf8bd2d..4465a72d 100644
--- a/src/frontend/index.tsx
+++ b/src/frontend/index.tsx
@@ -21,7 +21,7 @@ function renderToolbarButtonApp(rootElement: HTMLElement) {
   renderRoot(rootElement, <ToolbarButtonApp />);
 }
 
-export async function render(): Promise<void> {
+export function render() {
   const addressBarRoot = document.getElementById('address-bar-root');
   const introRoot = document.getElementById('intro-root');
   const optionsRoot = document.getElementById('options-root');
diff --git a/src/frontend/toolbar-button/NotificationsListItem/index.tsx b/src/frontend/toolbar-button/NotificationsListItem/index.tsx
index 6030e995..031cc1fa 100644
--- a/src/frontend/toolbar-button/NotificationsListItem/index.tsx
+++ b/src/frontend/toolbar-button/NotificationsListItem/index.tsx
@@ -138,7 +138,7 @@ function wrapLinks(pontoonBaseUrl: string): HTMLReactParserOptions['replace'] {
 
 async function openTeamProject(projectUrl: string): Promise<void> {
   const teamProjectUrl = await getTeamProjectUrl(projectUrl);
-  openNewPontoonTab(teamProjectUrl);
+  await openNewPontoonTab(teamProjectUrl);
   window.close();
 }