diff --git a/lib/isccfg/namedconf.c b/lib/isccfg/namedconf.c
index e1b1ba5c24..a8028b9df1 100644
--- a/lib/isccfg/namedconf.c
+++ b/lib/isccfg/namedconf.c
@@ -10,6 +10,7 @@
 
 #include <config.h>
 
+#include <stdlib.h>
 #include <string.h>
 
 #include <isc/lex.h>