diff --git a/headers/private/fs_shell/fssh_auto_locker.h b/headers/private/fs_shell/fssh_auto_locker.h
index 628487bfb1..ac377fe39e 100644
--- a/headers/private/fs_shell/fssh_auto_locker.h
+++ b/headers/private/fs_shell/fssh_auto_locker.h
@@ -6,6 +6,9 @@
 #define _FSSH_AUTO_LOCKER_H
 
 
+#include <stddef.h>
+
+
 namespace FSShell {
 
 // AutoLockerStandardLocking