diff --git a/fs/internal.h b/fs/internal.h
index e96a166..8a03a54 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -70,6 +70,8 @@
 
 extern void __init mnt_init(void);
 
+extern spinlock_t vfsmount_lock;
+
 /*
  * fs_struct.c
  */