diff --git a/build_tools/vercomp.c b/build_tools/vercomp.c
index acc32f181a6107988aa6357026555ccefe13e682..b2ba102af23a4b06b4c967bc35c790e76a5e84f0 100755
--- a/build_tools/vercomp.c
+++ b/build_tools/vercomp.c
@@ -20,6 +20,7 @@
 
 */
 
+#include <stdlib.h>
 #include <stdio.h>
 #include <string.h>