diff --git a/src/vs/workbench/api/common/extHostTesting.ts b/src/vs/workbench/api/common/extHostTesting.ts
index 5e2e6f1bc19..d17a5a2c76a 100644
--- a/src/vs/workbench/api/common/extHostTesting.ts
+++ b/src/vs/workbench/api/common/extHostTesting.ts
@@ -138,10 +138,12 @@ export class ExtHostTesting implements ExtHostTestingShape {
 			createTestRun: (request, name, persist = true) => {
 				return this.runTracker.createTestRun(controllerId, collection, request, name, persist);
 			},
-			invalidateTestResults: item => {
+			invalidateTestResults: items => {
 				checkProposedApiEnabled(extension, 'testInvalidateResults');
-				const id = item ? TestId.fromExtHostTestItem(item, controllerId).toString() : controllerId;
-				return this.proxy.$markTestRetired(id);
+				for (const item of items instanceof Array ? items : [items]) {
+					const id = item ? TestId.fromExtHostTestItem(item, controllerId).toString() : controllerId;
+					this.proxy.$markTestRetired(id);
+				}
 			},
 			set resolveHandler(fn) {
 				collection.resolveHandler = fn;
diff --git a/src/vscode-dts/vscode.proposed.testInvalidateResults.d.ts b/src/vscode-dts/vscode.proposed.testInvalidateResults.d.ts
index 35f955c2f4d..87d21c13c16 100644
--- a/src/vscode-dts/vscode.proposed.testInvalidateResults.d.ts
+++ b/src/vscode-dts/vscode.proposed.testInvalidateResults.d.ts
@@ -25,6 +25,6 @@ declare module 'vscode' {
 		 *
 		 * @param item Item to mark as outdated. If undefined, all the controller's items are marked outdated.
 		 */
-		invalidateTestResults(item?: TestItem): void;
+		invalidateTestResults(items?: TestItem | readonly TestItem[]): void;
 	}
 }