diff --git a/testing/ostest/tls.c b/testing/ostest/tls.c
index 54ec3bca6..03227e3a9 100644
--- a/testing/ostest/tls.c
+++ b/testing/ostest/tls.c
@@ -29,6 +29,7 @@
 #include <stdio.h>
 #include <string.h>
 
+#include <nuttx/arch.h>
 #include <nuttx/tls.h>
 
 #include "ostest.h"