diff --git a/mingw-w64-headers/include/oaidl.h b/mingw-w64-headers/include/oaidl.h
index c0df4ae..b538c52 100755
--- a/mingw-w64-headers/include/oaidl.h
+++ b/mingw-w64-headers/include/oaidl.h
@@ -235,7 +235,7 @@
 #define FADF_VARIANT (0x800)
 #define FADF_RESERVED (0xf008)
 
-#if (__STDC__ && !defined(_FORCENAMELESSUNION)) || defined(NONAMELESSUNION)
+#if !defined(_FORCENAMELESSUNION) || defined(NONAMELESSUNION)
 #define __VARIANT_NAME_1 n1
 #define __VARIANT_NAME_2 n2
 #define __VARIANT_NAME_3 n3
@@ -493,17 +493,31 @@
   } EXCEPINFO,*LPEXCEPINFO;
 
   typedef enum tagCALLCONV {
-    CC_FASTCALL = 0,CC_CDECL = 1,CC_MSCPASCAL = CC_CDECL + 1,CC_PASCAL = CC_MSCPASCAL,CC_MACPASCAL = CC_PASCAL + 1,CC_STDCALL = CC_MACPASCAL + 1,
-    CC_FPFASTCALL = CC_STDCALL + 1,CC_SYSCALL = CC_FPFASTCALL + 1,CC_MPWCDECL = CC_SYSCALL + 1,CC_MPWPASCAL = CC_MPWCDECL + 1,CC_MAX = CC_MPWPASCAL + 1
+    CC_FASTCALL = 0,
+    CC_CDECL = 1,CC_MSCPASCAL = 2,
+    CC_PASCAL = CC_MSCPASCAL,
+    CC_MACPASCAL = 3,
+    CC_STDCALL = 4,
+    CC_FPFASTCALL = 5,
+    CC_SYSCALL = 6,
+    CC_MPWCDECL = 7,
+    CC_MPWPASCAL = 8,
+    CC_MAX = 9
   } CALLCONV;
 
   typedef enum tagFUNCKIND {
-    FUNC_VIRTUAL = 0,FUNC_PUREVIRTUAL = FUNC_VIRTUAL + 1,FUNC_NONVIRTUAL = FUNC_PUREVIRTUAL + 1,FUNC_STATIC = FUNC_NONVIRTUAL + 1,
-    FUNC_DISPATCH = FUNC_STATIC + 1
+    FUNC_VIRTUAL = 0,
+    FUNC_PUREVIRTUAL = 1,
+    FUNC_NONVIRTUAL = 2,
+    FUNC_STATIC = 3,
+    FUNC_DISPATCH = 4
   } FUNCKIND;
 
   typedef enum tagINVOKEKIND {
-    INVOKE_FUNC = 1,INVOKE_PROPERTYGET = 2,INVOKE_PROPERTYPUT = 4,INVOKE_PROPERTYPUTREF = 8
+    INVOKE_FUNC = 1,
+    INVOKE_PROPERTYGET = 2,
+    INVOKE_PROPERTYPUT = 4,
+    INVOKE_PROPERTYPUTREF = 8
   } INVOKEKIND;
 
   typedef struct tagFUNCDESC {
diff --git a/mingw-w64-headers/include/oleauto.h b/mingw-w64-headers/include/oleauto.h
index d9705bf..39785e8 100755
--- a/mingw-w64-headers/include/oleauto.h
+++ b/mingw-w64-headers/include/oleauto.h
@@ -650,17 +650,10 @@
 WINOLEAUTAPI_(ULONG) OaBuildVersion(void);
 WINOLEAUTAPI_(void) ClearCustData(LPCUSTDATA pCustData);
 
-#if __STDC__ || defined(NONAMELESSUNION)
 #define V_UNION(X,Y) ((X)->n1.n2.n3.Y)
 #define V_VT(X) ((X)->n1.n2.vt)
 #define V_RECORDINFO(X) ((X)->n1.n2.n3.brecVal.pRecInfo)
 #define V_RECORD(X) ((X)->n1.n2.n3.brecVal.pvRecord)
-#else
-#define V_UNION(X,Y) ((X)->Y)
-#define V_VT(X) ((X)->vt)
-#define V_RECORDINFO(X) ((X)->pRecInfo)
-#define V_RECORD(X) ((X)->pvRecord)
-#endif
 
 #define V_ISBYREF(X) (V_VT(X)&VT_BYREF)
 #define V_ISARRAY(X) (V_VT(X)&VT_ARRAY)