diff --git a/xcode/config.h b/xcode/config.h
index 5c892eb..7a23195 100644
--- a/xcode/config.h
+++ b/xcode/config.h
@@ -164,10 +164,10 @@
 
 /* The size of `long', as computed by sizeof. */
 #ifndef __LP64__
-# define SIZEOF_LONG 4
-#else
-# define SIZEOF_LONG 8
-#endif
+#define SIZEOF_LONG 4
+#else /* __LP64__ */
+#define SIZEOF_LONG 8
+#endif /* __LP64__ */
 
 /* The size of `long long', as computed by sizeof. */
 #define SIZEOF_LONG_LONG 8
@@ -180,10 +180,10 @@
 
 /* The size of `size_t', as computed by sizeof. */
 #ifndef __LP64__
-# define SIZEOF_SIZE_T 4
-#else
-# define SIZEOF_SIZE_T 8
-#endif
+#define SIZEOF_SIZE_T 4
+#else /* __LP64__ */
+#define SIZEOF_SIZE_T 8
+#endif /* __LP64__ */
 
 /* Define to 1 if you have the ANSI C header files. */
 #define STDC_HEADERS 1
diff --git a/xcode/mkconfig-h.sh b/xcode/mkconfig-h.sh
new file mode 100755
index 0000000..43199f7
--- /dev/null
+++ b/xcode/mkconfig-h.sh
@@ -0,0 +1,12 @@
+#!/bin/sh
+
+DIR=tmp.$$
+
+mkdir -p $DIR/32 $DIR/64
+
+(cd $DIR/32; ../../../configure CFLAGS=-m32)
+(cd $DIR/64; ../../../configure CFLAGS=-m64)
+
+diff -D __LP64__ $DIR/32/config.h $DIR/64/config.h > config.h
+
+rm -r $DIR