diff --git a/packages/core/src/event_emitter.ts b/packages/core/src/event_emitter.ts
index e7b255072b..07143d9774 100644
--- a/packages/core/src/event_emitter.ts
+++ b/packages/core/src/event_emitter.ts
@@ -62,12 +62,8 @@ import {Subject, Subscription} from 'rxjs';
  * @publicApi
  */
 export class EventEmitter<T extends any> extends Subject<T> {
-  // TODO: mark this as internal once all the facades are gone
-  // we can't mark it as internal now because EventEmitter exported via @angular/core would not
-  // contain this property making it incompatible with all the code that uses EventEmitter via
-  // facades, which are local to the code and do not have this property stripped.
   /**
-   * Internal
+   * @internal
    */
   __isAsync: boolean;  // tslint:disable-line
 
diff --git a/tools/public_api_guard/core/core.d.ts b/tools/public_api_guard/core/core.d.ts
index 70919a41bc..4bb2faacd3 100644
--- a/tools/public_api_guard/core/core.d.ts
+++ b/tools/public_api_guard/core/core.d.ts
@@ -326,7 +326,6 @@ export declare class ErrorHandler {
 }
 
 export declare class EventEmitter<T extends any> extends Subject<T> {
-    __isAsync: boolean;
     constructor(isAsync?: boolean);
     emit(value?: T): void;
     subscribe(generatorOrNext?: any, error?: any, complete?: any): Subscription;