diff --git a/reactos/include/psdk/winnt.h b/reactos/include/psdk/winnt.h
index 2077732bd2f..25ff67708ec 100644
--- a/reactos/include/psdk/winnt.h
+++ b/reactos/include/psdk/winnt.h
@@ -313,6 +313,22 @@ typedef DWORD FLONG;
 #define ERROR_SEVERITY_INFORMATIONAL 0x40000000
 #define ERROR_SEVERITY_WARNING       0x80000000
 #define ERROR_SEVERITY_ERROR         0xC0000000
+
+#ifdef __cplusplus
+#define DEFINE_ENUM_FLAG_OPERATORS(ENUMTYPE) \
+extern "C++" { \
+    inline ENUMTYPE operator | (ENUMTYPE a, ENUMTYPE b) { return ENUMTYPE(((int)a)|((int)b)); } \
+    inline ENUMTYPE operator |= (ENUMTYPE &a, ENUMTYPE b) { return (ENUMTYPE &)(((int &)a) |= ((int)b)); } \
+    inline ENUMTYPE operator & (ENUMTYPE a, ENUMTYPE b) { return ENUMTYPE(((int)a)&((int)b)); } \
+    inline ENUMTYPE operator &= (ENUMTYPE &a, ENUMTYPE b) { return (ENUMTYPE &)(((int &)a) &= ((int)b)); } \
+    inline ENUMTYPE operator ~ (ENUMTYPE a) { return (ENUMTYPE)(~((int)a)); } \
+    inline ENUMTYPE operator ^ (ENUMTYPE a, ENUMTYPE b) { return ENUMTYPE(((int)a)^((int)b)); } \
+    inline ENUMTYPE operator ^= (ENUMTYPE &a, ENUMTYPE b) { return (ENUMTYPE &)(((int &)a) ^= ((int)b)); } \
+}
+#else
+#define DEFINE_ENUM_FLAG_OPERATORS(ENUMTYPE) /* */
+#endif
+
 /* also in ddk/ntifs.h */
 #define COMPRESSION_FORMAT_NONE         (0x0000)
 #define COMPRESSION_FORMAT_DEFAULT      (0x0001)