diff --git a/intern/string/intern/STR_String.cpp b/intern/string/intern/STR_String.cpp
index 506e241ecae..0586907d7c5 100644
--- a/intern/string/intern/STR_String.cpp
+++ b/intern/string/intern/STR_String.cpp
@@ -39,6 +39,7 @@
 
 #include <stdio.h>
 #include <stdarg.h>
+#include <stdlib.h> 
 #include "STR_String.h"
 
 #ifdef HAVE_CONFIG_H