diff --git a/hash.h b/hash.h
index 3e7854b..73f961b 100644
--- a/hash.h
+++ b/hash.h
@@ -1,5 +1,8 @@
 #ifndef _LINUX_HASH_H
 #define _LINUX_HASH_H
+
+#include "arch/arch.h"
+
 /* Fast hashing routine for a long.
    (C) 2002 William Lee Irwin III, IBM */
 
@@ -14,12 +17,6 @@
  * machines where multiplications are slow.
  */
 
-#ifdef __WORDSIZE
-#define BITS_PER_LONG	__WORDSIZE
-#else
-#define BITS_PER_LONG	32
-#endif
-
 #if BITS_PER_LONG == 32
 /* 2^31 + 2^29 - 2^25 + 2^22 - 2^19 - 2^16 + 1 */
 #define GOLDEN_RATIO_PRIME 0x9e370001UL