diff --git a/Platform/user/ulog/ulog-api/ulog_api.c b/Platform/user/ulog/ulog-api/ulog_api.c
index 912752ede..77be8c31a 100755
--- a/Platform/user/ulog/ulog-api/ulog_api.c
+++ b/Platform/user/ulog/ulog-api/ulog_api.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdlib.h>
 #include <stdarg.h>
 
 #include "ulog.h"