diff --git a/dlls/mmdevapi/audio.c b/dlls/mmdevapi/audio.c
index 2d19c059d9..b166d81338 100644
--- a/dlls/mmdevapi/audio.c
+++ b/dlls/mmdevapi/audio.c
@@ -1107,7 +1107,8 @@ static HRESULT WINAPI ACR_ReleaseBuffer(IAudioRenderClient *iface, UINT32 writte
         return E_INVALIDARG;
 
     if (!written) {
-        FIXME("Handled right?\n");
+        if (This->parent->locked)
+            FIXME("Handled right?\n");
         This->parent->locked = 0;
         return S_OK;
     }