diff --git a/dlls/mf/tests/mf.c b/dlls/mf/tests/mf.c
index 72170b6be5f..743946f7fba 100644
--- a/dlls/mf/tests/mf.c
+++ b/dlls/mf/tests/mf.c
@@ -2939,7 +2939,7 @@ static HRESULT WINAPI test_grabber_callback_OnProcessSample(IMFSampleGrabberSink
 
     SetEvent(grabber->ready_event);
     res = WaitForSingleObject(grabber->done_event, 1000);
-    ok(!res, "WaitForSingleObject returned %#lx", res);
+    ok(!res, "WaitForSingleObject returned %#lx\n", res);
 
     return S_OK;
 }