--- des.h.orig	2016-02-26 21:31:07.204547590 +0100
+++ des.h	2016-02-26 21:32:19.964190512 +0100
@@ -72,11 +72,14 @@
 #endif
 
 #include <stdio.h>
+#include <stdint.h>
 
 /* If this is set to 'unsigned int' on a DEC Alpha, this gives about a
  * %20 speed up (longs are 8 bytes, int's are 4). */
+/* On PCs with 64-bit Linux 'unsigned long' doesn't work, 'destest'
+ * fails. 'unsigned int' or 'uint32_t' is needed. */
 #ifndef DES_LONG
-#define DES_LONG unsigned long
+#define DES_LONG uint32_t
 #endif
 
 typedef unsigned char des_cblock[8];