diff --git a/clients/ud/string_to_key.c b/clients/ud/string_to_key.c
index 3f53a0f41e..9160afba30 100644
--- a/clients/ud/string_to_key.c
+++ b/clients/ud/string_to_key.c
@@ -122,7 +122,7 @@ des_string_to_key( char *str, register des_cblock *key )
 #ifdef USE_DES_DEBUG
     if (des_debug)
 	fprintf(stdout,
-		"\nResulting string_to_key = 0x%x 0x%x\n",
+		"\nResulting string_to_key = 0x%lx 0x%lx\n",
 		*((unsigned long *) key),
 		*((unsigned long *) key+1));
 #endif