diff --git a/apps/app_sms.c b/apps/app_sms.c
index 6baeaf80ee..6e3be3f94e 100755
--- a/apps/app_sms.c
+++ b/apps/app_sms.c
@@ -21,6 +21,7 @@
 #include <unistd.h>
 #include <string.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <errno.h>
 #include <sys/types.h>
 #include <dirent.h>