diff --git a/src/vs/workbench/api/browser/mainThreadTesting.ts b/src/vs/workbench/api/browser/mainThreadTesting.ts
index b440572b157..960f38b305e 100644
--- a/src/vs/workbench/api/browser/mainThreadTesting.ts
+++ b/src/vs/workbench/api/browser/mainThreadTesting.ts
@@ -37,7 +37,6 @@ const reviveDiff = (diff: TestsDiff) => {
 export class MainThreadTesting extends Disposable implements MainThreadTestingShape, ITestRootProvider {
 	private readonly proxy: ExtHostTestingShape;
 	private readonly diffListener = this._register(new MutableDisposable());
-	private readonly testSubscriptions = new Map<string, IDisposable>();
 	private readonly testProviderRegistrations = new Map<string, IDisposable>();
 
 	constructor(
@@ -205,10 +204,10 @@ export class MainThreadTesting extends Disposable implements MainThreadTestingSh
 
 	public override dispose() {
 		super.dispose();
-		for (const subscription of this.testSubscriptions.values()) {
+		for (const subscription of this.testProviderRegistrations.values()) {
 			subscription.dispose();
 		}
-		this.testSubscriptions.clear();
+		this.testProviderRegistrations.clear();
 	}
 
 	private withLiveRun<T>(runId: string, fn: (run: LiveTestResult) => T): T | undefined {
diff --git a/src/vs/workbench/contrib/testing/common/testServiceImpl.ts b/src/vs/workbench/contrib/testing/common/testServiceImpl.ts
index a9bf1a2ea8a..30f84c9db12 100644
--- a/src/vs/workbench/contrib/testing/common/testServiceImpl.ts
+++ b/src/vs/workbench/contrib/testing/common/testServiceImpl.ts
@@ -16,7 +16,7 @@ import { IWorkspaceTrustRequestService } from 'vs/platform/workspace/common/work
 import { MainThreadTestCollection } from 'vs/workbench/contrib/testing/common/mainThreadTestCollection';
 import { MutableObservableValue } from 'vs/workbench/contrib/testing/common/observableValue';
 import { StoredValue } from 'vs/workbench/contrib/testing/common/storedValue';
-import { RunTestsRequest, ITestIdWithSrc, TestsDiff } from 'vs/workbench/contrib/testing/common/testCollection';
+import { RunTestsRequest, ITestIdWithSrc, TestsDiff, TestDiffOpType } from 'vs/workbench/contrib/testing/common/testCollection';
 import { TestingContextKeys } from 'vs/workbench/contrib/testing/common/testingContextKeys';
 import { ITestResult } from 'vs/workbench/contrib/testing/common/testResult';
 import { ITestResultService } from 'vs/workbench/contrib/testing/common/testResultService';
@@ -195,6 +195,15 @@ export class TestService extends Disposable implements ITestService {
 		this.providerCount.set(this.testControllers.size);
 
 		return toDisposable(() => {
+			const diff: TestsDiff = [];
+			for (const root of this.collection.rootItems) {
+				if (root.controllerId === id) {
+					diff.push([TestDiffOpType.Remove, root.item.extId]);
+				}
+			}
+
+			this.publishDiff(id, diff);
+
 			if (this.testControllers.delete(id)) {
 				this.providerCount.set(this.testControllers.size);
 			}