diff --git a/src/vs/workbench/services/extensions/worker/polyfillNestedWorker.ts b/src/vs/workbench/services/extensions/worker/polyfillNestedWorker.ts
index f70257dafd7..da0a8f5a574 100644
--- a/src/vs/workbench/services/extensions/worker/polyfillNestedWorker.ts
+++ b/src/vs/workbench/services/extensions/worker/polyfillNestedWorker.ts
@@ -90,7 +90,7 @@ export class NestedWorker extends EventTarget implements Worker {
 				type: '_terminateWorker',
 				id
 			};
-			channel.port1.postMessage(msg);
+			nativePostMessage(msg);
 			URL.revokeObjectURL(blobUrl);
 
 			channel.port1.close();