diff --git a/reactos/include/ddk/portcls.h b/reactos/include/ddk/portcls.h
index c74f836fcf7..d346917a6e6 100644
--- a/reactos/include/ddk/portcls.h
+++ b/reactos/include/ddk/portcls.h
@@ -1098,7 +1098,7 @@ DECLARE_INTERFACE_(IPortWavePci, IPort)
 #define STATIC_IPortWavePciStream \
     0xb4c90a51L, 0x5791, 0x11d0, 0x86, 0xf9, 0x00, 0xa0, 0xc9, 0x11, 0xb5, 0x44
 
-DEFINE_GUIDSTRUCT("0xB4C90A51-5791-11d0-86f9-00a0c911b544", IID_IPortWavePciStream);
+DEFINE_GUID(IID_IPortWavePciStream, 0xb4c90a51L, 0x5791, 0x11d0, 0x86, 0xf9, 0x00, 0xa0, 0xc9, 0x11, 0xb5, 0x44);
 
 /* ... */
 
diff --git a/reactos/include/ddk/stdunk.h b/reactos/include/ddk/stdunk.h
index 060d30be795..d653216a1f6 100644
--- a/reactos/include/ddk/stdunk.h
+++ b/reactos/include/ddk/stdunk.h
@@ -12,6 +12,8 @@
 #ifndef STDUNK_H
 #define STDUNK_H
 
+#define STDUNK_TAG(A, B, C, D) (ULONG)(((A)<<0) + ((B)<<8) + ((C)<<16) + ((D)<<24))
+
 #include <punknown.h>
 
 /* ===============================================================
@@ -152,7 +154,7 @@ typedef struct CUnknown
     STD_CREATE_BODY_WITH_TAG_(classname, unknown, outer_unknown, pool_type, tag, PUNKNOWN)
 
 #define STD_CREATE_BODY_(classname, unknown, outer_unknown, pool_type, base) \
-    STD_CREATE_BODY_WITH_TAG_(classname, unknown, outer_unknown, pool_type, 'rCcP', base)
+    STD_CREATE_BODY_WITH_TAG_(classname, unknown, outer_unknown, pool_type, STDUNK_TAG('r','C','c','P'), base)
 
 #define STD_CREATE_BODY(classname, unknown, outer_unknown, pool_type) \
     STD_CREATE_BODY_(classname, unknown, outer_unknown, pool_type, PUNKNOWN)
@@ -186,7 +188,7 @@ operator new (
     size_t  size,
     POOL_TYPE pool_type)
 {
-    return KCOM_New(size, pool_type, 'wNcP');
+    return KCOM_New(size, pool_type, STDUNK_TAG ('w','N','c','P'));
 }
 
 inline PVOID