diff --git a/crypto/cast/cast.h b/crypto/cast/cast.h
index 90b45b950aa8dcbc2b2156c3523c8a337281b3d3..79bb297c1a05da9204ee801dba1b043cbb02ba38 100644
--- a/crypto/cast/cast.h
+++ b/crypto/cast/cast.h
@@ -72,7 +72,7 @@ extern "C" {
 #define CAST_ENCRYPT	1
 #define CAST_DECRYPT	0
 
-#define CAST_LONG unsigned long
+#define CAST_LONG unsigned int
 
 #define CAST_BLOCK	8
 #define CAST_KEY_LENGTH	16