diff --git a/dlls/mfplat/tests/mfplat.c b/dlls/mfplat/tests/mfplat.c
index 832b52713c7..1db4d2dcc47 100644
--- a/dlls/mfplat/tests/mfplat.c
+++ b/dlls/mfplat/tests/mfplat.c
@@ -1712,6 +1712,8 @@ todo_wine
 todo_wine
     ok(count == 1, "Unexpected buffer count %u.\n", count);
 
+    IMFMediaBuffer_Release(buffer);
+
     IMFSample_Release(sample);
 }