diff --git a/components/utilities/ulog/ulog.c b/components/utilities/ulog/ulog.c
index 4918a68339..8f8782f4c0 100644
--- a/components/utilities/ulog/ulog.c
+++ b/components/utilities/ulog/ulog.c
@@ -9,6 +9,7 @@
  */
 
 #include <stdarg.h>
+#include <stdlib.h>
 #include "ulog.h"
 #include "rthw.h"