diff --git a/msc.cmake b/msc.cmake
index 603e781bcb8..029e186b231 100644
--- a/msc.cmake
+++ b/msc.cmake
@@ -131,7 +131,7 @@ endmacro()
 
 #idl files support
 set(IDL_COMPILER midl)
-set(IDL_FLAGS /win32)
+set(IDL_FLAGS /win32 /DIEnumVARIANT=IEnumXVARIANT)
 set(IDL_HEADER_ARG /h) #.h
 set(IDL_TYPELIB_ARG /tlb) #.tlb
 set(IDL_SERVER_ARG /sstub) #.c for stub server library