diff --git a/include/mfreadwrite.idl b/include/mfreadwrite.idl
index 3b1318e977b..46eb5dc9c0f 100644
--- a/include/mfreadwrite.idl
+++ b/include/mfreadwrite.idl
@@ -23,6 +23,7 @@ typedef [v1_enum] enum MF_SOURCE_READER_CONTROL_FLAG
 {
     MF_SOURCE_READER_CONTROLF_DRAIN = 0x00000001,
 } MF_SOURCE_READER_CONTROL_FLAG;
+cpp_quote("DEFINE_ENUM_FLAG_OPERATORS(MF_SOURCE_READER_CONTROL_FLAG)")
 
 enum
 {
@@ -45,6 +46,7 @@ typedef [v1_enum] enum MF_SOURCE_READER_FLAG
     MF_SOURCE_READERF_STREAMTICK              = 0x00000100,
     MF_SOURCE_READERF_ALLEFFECTSREMOVED       = 0x00000200,
 } MF_SOURCE_READER_FLAG;
+cpp_quote("DEFINE_ENUM_FLAG_OPERATORS(MF_SOURCE_READER_FLAG)")
 
 enum
 {