diff --git a/lib/dns/zone.c b/lib/dns/zone.c
index 8180a6a649..4986dbd1b9 100644
--- a/lib/dns/zone.c
+++ b/lib/dns/zone.c
@@ -15,12 +15,13 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: zone.c,v 1.619 2011/07/08 23:47:54 tbox Exp $ */
+/* $Id: zone.c,v 1.620 2011/07/20 14:28:24 ckb Exp $ */
 
 /*! \file */
 
 #include <config.h>
 #include <errno.h>
+#include <stdlib.h>
 
 #include <isc/file.h>
 #include <isc/mutex.h>