diff --git a/lib-src/hexl.c b/lib-src/hexl.c
index 5d71033d434..9731321d4ae 100644
--- a/lib-src/hexl.c
+++ b/lib-src/hexl.c
@@ -1,3 +1,7 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
 #include <stdio.h>
 #include <ctype.h>
 #ifdef DOS_NT