diff --git a/src/GeoIP-1.4.0/libGeoIP/md5.c b/src/GeoIP-1.4.0/libGeoIP/md5.c
index fc761cc..922f75a 100644
--- a/src/GeoIP-1.4.0/libGeoIP/md5.c
+++ b/src/GeoIP-1.4.0/libGeoIP/md5.c
@@ -23,6 +23,8 @@
 /* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.  */
 /* Heavily modified for GnuPG by <wk@gnupg.org> */
 
+#include "config.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>