diff --git a/dlls/qasf/dmowrapper.c b/dlls/qasf/dmowrapper.c
index 76704f88cd4..18d40a5671a 100644
--- a/dlls/qasf/dmowrapper.c
+++ b/dlls/qasf/dmowrapper.c
@@ -703,6 +703,7 @@ static HRESULT dmo_wrapper_cleanup_stream(struct strmbase_filter *iface)
 
     IUnknown_QueryInterface(filter->dmo, &IID_IMediaObject, (void **)&dmo);
 
+    EnterCriticalSection(&filter->filter.stream_cs);
     for (i = 0; i < filter->source_count; ++i)
     {
         if (filter->sources[i].pin.pin.peer)
@@ -712,6 +713,7 @@ static HRESULT dmo_wrapper_cleanup_stream(struct strmbase_filter *iface)
     IMediaObject_Flush(dmo);
 
     IMediaObject_Release(dmo);
+    LeaveCriticalSection(&filter->filter.stream_cs);
     return S_OK;
 }
 
diff --git a/dlls/qasf/tests/dmowrapper.c b/dlls/qasf/tests/dmowrapper.c
index 70dcc0c453e..388004de783 100644
--- a/dlls/qasf/tests/dmowrapper.c
+++ b/dlls/qasf/tests/dmowrapper.c
@@ -1740,7 +1740,6 @@ static void test_sample_processing(IMediaControl *control, IMemInputPin *input,
     stop_thread = CreateThread(NULL, 0, stop_filter_proc, dmo_filter, 0, NULL);
     ok(!!stop_thread, "CreateThread returned NULL thread.\n");
     ret = WaitForSingleObject(stop_thread, 200);
-    todo_wine
     ok(ret == WAIT_TIMEOUT, "WaitForSingleObject returned %#lx.\n", ret);
     /* Signal event to end Receive(). */
     SetEvent(testsink->event);