diff --git a/src/vs/workbench/contrib/extensions/browser/extensionRecommendationNotificationService.ts b/src/vs/workbench/contrib/extensions/browser/extensionRecommendationNotificationService.ts
index 7aa8ac10873..e840bd9b331 100644
--- a/src/vs/workbench/contrib/extensions/browser/extensionRecommendationNotificationService.ts
+++ b/src/vs/workbench/contrib/extensions/browser/extensionRecommendationNotificationService.ts
@@ -361,7 +361,7 @@ export class ExtensionRecommendationNotificationService extends Disposable imple
 				this.visibleNotification = { recommendationsNotification, source, from: Date.now() };
 				recommendationsNotification.show();
 			}
-			await raceCancellation(Event.toPromise(recommendationsNotification.onDidClose), token);
+			await raceCancellation(new Promise(c => disposables.add(Event.once(recommendationsNotification.onDidClose)(c))), token);
 			return !recommendationsNotification.isCancelled();
 		} finally {
 			disposables.dispose();
diff --git a/src/vs/workbench/contrib/extensions/test/electron-sandbox/extensionRecommendationsService.test.ts b/src/vs/workbench/contrib/extensions/test/electron-sandbox/extensionRecommendationsService.test.ts
index 82b0f4d4298..c644f0acb11 100644
--- a/src/vs/workbench/contrib/extensions/test/electron-sandbox/extensionRecommendationsService.test.ts
+++ b/src/vs/workbench/contrib/extensions/test/electron-sandbox/extensionRecommendationsService.test.ts
@@ -61,7 +61,9 @@ import { VSBuffer } from 'vs/base/common/buffer';
 import { platform } from 'vs/base/common/platform';
 import { arch } from 'vs/base/common/process';
 import { runWithFakedTimers } from 'vs/base/test/common/timeTravelScheduler';
+import { ensureNoDisposablesAreLeakedInTestSuite } from 'vs/base/test/common/utils';
 import { DisposableStore } from 'vs/base/common/lifecycle';
+import { timeout } from 'vs/base/common/async';
 
 const mockExtensionGallery: IGalleryExtension[] = [
 	aGalleryExtension('MockExtension1', {
@@ -181,7 +183,7 @@ function aGalleryExtension(name: string, properties: any = {}, galleryExtensionP
 }
 
 suite('ExtensionRecommendationsService Test', () => {
-	const disposableStore = new DisposableStore();
+	let disposableStore: DisposableStore;
 	let workspaceService: IWorkspaceContextService;
 	let instantiationService: TestInstantiationService;
 	let testConfigurationService: TestConfigurationService;
@@ -194,7 +196,15 @@ suite('ExtensionRecommendationsService Test', () => {
 	let promptedEmitter: Emitter<void>;
 	let onModelAddedEvent: Emitter<ITextModel>;
 
+	teardown(async () => {
+		disposableStore.dispose();
+		await timeout(0); // allow for async disposables to complete
+	});
+
+	ensureNoDisposablesAreLeakedInTestSuite();
+
 	setup(() => {
+		disposableStore = new DisposableStore();
 		instantiationService = disposableStore.add(new TestInstantiationService());
 		promptedEmitter = disposableStore.add(new Emitter<void>());
 		installEvent = disposableStore.add(new Emitter<InstallExtensionEvent>());
@@ -308,8 +318,6 @@ suite('ExtensionRecommendationsService Test', () => {
 		});
 	});
 
-	teardown(() => disposableStore.clear());
-
 	function setUpFolderWorkspace(folderName: string, recommendedExtensions: string[], ignoredRecommendations: string[] = []): Promise<void> {
 		return setUpFolder(folderName, recommendedExtensions, ignoredRecommendations);
 	}