diff --git a/include/wmcodecdsp.idl b/include/wmcodecdsp.idl
index ae2a42419b4..4ad965ab3d9 100644
--- a/include/wmcodecdsp.idl
+++ b/include/wmcodecdsp.idl
@@ -45,6 +45,11 @@ coclass CMSH264DecoderMFT {}
 ]
 coclass CWMADecMediaObject {};
 
+[
+    uuid(70f598e9-f4ab-495a-99e2-a7c4d3d89abf)
+]
+coclass CWMAEncMediaObject {};
+
 [
     uuid(93af0c51-2275-45d2-a35b-f2ba21caed00)
 ]