diff --git a/src/ows/ows_config.c b/src/ows/ows_config.c
index 9bdf605..ba4ea97 100644
--- a/src/ows/ows_config.c
+++ b/src/ows/ows_config.c
@@ -22,6 +22,7 @@
 
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <assert.h>
 #include <libxml/xmlreader.h>