diff --git a/include/mapidefs.h b/include/mapidefs.h
index 6f8c49b8e42..10ca3fc282b 100644
--- a/include/mapidefs.h
+++ b/include/mapidefs.h
@@ -41,12 +41,12 @@ typedef unsigned long           LHANDLE, *LPLHANDLE;
 typedef union tagCY
 {
    struct {
-#ifdef BIG_ENDIAN
-        long Hi;
-        long Lo;
+#ifdef WORDS_BIGENDIAN
+       LONG Hi;
+       ULONG Lo;
 #else
-      unsigned long Lo;
-      long Hi;
+       ULONG Lo;
+       LONG Hi;
 #endif
    } u;
    LONGLONG int64;
diff --git a/include/wtypes.h b/include/wtypes.h
index e8deba59962..4b8fc0d5a39 100644
--- a/include/wtypes.h
+++ b/include/wtypes.h
@@ -166,13 +166,13 @@ typedef struct tagBLOB
 
 typedef union tagCY {
     struct {
-#ifdef BIG_ENDIAN
+#ifdef WORDS_BIGENDIAN
         LONG  Hi;
         ULONG Lo;
-#else /* defined(BIG_ENDIAN) */
+#else
         ULONG Lo;
         LONG  Hi;
-#endif /* defined(BIG_ENDIAN) */
+#endif
     } DUMMYSTRUCTNAME;
     LONGLONG int64;
 } CY;
@@ -191,13 +191,13 @@ typedef struct tagDEC {
     ULONG Hi32;
     union {
         struct {
-#ifdef BIG_ENDIAN
+#ifdef WORDS_BIGENDIAN
             ULONG Mid32;
             ULONG Lo32;
-#else /* defined(BIG_ENDIAN) */
+#else
             ULONG Lo32;
             ULONG Mid32;
-#endif /* defined(BIG_ENDIAN) */
+#endif
         } DUMMYSTRUCTNAME2;
         ULONGLONG Lo64;
     } DUMMYUNIONNAME2;