diff --git a/dlls/mfreadwrite/main.c b/dlls/mfreadwrite/main.c
index e09120d5a4b..2a5e29a48ea 100644
--- a/dlls/mfreadwrite/main.c
+++ b/dlls/mfreadwrite/main.c
@@ -54,6 +54,17 @@ HRESULT WINAPI MFCreateSourceReaderFromMediaSource(IMFMediaSource *source, IMFAt
     return E_NOTIMPL;
 }
 
+HRESULT WINAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, void **ppv)
+{
+    FIXME("(%s,%s,%p)\n", debugstr_guid(rclsid), debugstr_guid(riid), ppv);
+    return CLASS_E_CLASSNOTAVAILABLE;
+}
+
+HRESULT WINAPI DllCanUnloadNow(void)
+{
+    return S_FALSE;
+}
+
 typedef struct _srcreader
 {
     IMFSourceReader IMFSourceReader_iface;
diff --git a/dlls/mfreadwrite/mfreadwrite.spec b/dlls/mfreadwrite/mfreadwrite.spec
index 4272b7183c2..f46c5923e29 100644
--- a/dlls/mfreadwrite/mfreadwrite.spec
+++ b/dlls/mfreadwrite/mfreadwrite.spec
@@ -1,5 +1,5 @@
-@ stub DllCanUnloadNow
-@ stub DllGetClassObject
+@ stdcall -private DllCanUnloadNow()
+@ stdcall -private DllGetClassObject(ptr ptr ptr)
 @ stub MFCreateSinkWriterFromMediaSink
 @ stub MFCreateSinkWriterFromURL
 @ stdcall MFCreateSourceReaderFromByteStream(ptr ptr ptr)