diff --git a/libaf/af.c b/libaf/af.c
index 77f30a4d45..1f7a1b0be8 100644
--- a/libaf/af.c
+++ b/libaf/af.c
@@ -16,6 +16,7 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#include "config.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>