$OpenBSD$
--- src/util.c.orig	Mon Sep  8 18:32:31 2014
+++ src/util.c	Mon Sep  8 18:32:52 2014
@@ -34,7 +34,7 @@ util_get_temp_filename(const char *prefix) 
 {
     struct timeval t;
     gettimeofday(&t, NULL);
-    char *filename = g_strdup_printf("%s%lu", prefix, t.tv_usec + t.tv_sec*1000000);
+    char *filename = g_strdup_printf("%s%lu", prefix, (long unsigned int)(t.tv_usec + t.tv_sec*1000000));
     char *cache_path = g_build_filename(dwb.files[FILES_CACHEDIR], filename, NULL);
     g_free(filename);
 
