diff --git a/spec/operators/timeout-spec.ts b/spec/operators/timeout-spec.ts
index f83392b248..59a894980d 100644
--- a/spec/operators/timeout-spec.ts
+++ b/spec/operators/timeout-spec.ts
@@ -686,8 +686,7 @@ describe('timeout operator', () => {
     });
   });
 
-  // TODO: fix firehose unsubscription
-  it.skip('should stop listening to a synchronous observable when unsubscribed', () => {
+  it('should stop listening to a synchronous observable when unsubscribed', () => {
     const sideEffects: number[] = [];
     const synchronousObservable = new Observable<number>(subscriber => {
       // This will check to see if the subscriber was closed on each loop