diff --git a/lib/isc/bind9.c b/lib/isc/bind9.c
index 9ca66d0f02..10cc350f43 100644
--- a/lib/isc/bind9.c
+++ b/lib/isc/bind9.c
@@ -16,6 +16,8 @@
 
 /*! \file */
 
+#include <config.h>
+
 #include <isc/bind9.h>
 
 /*