diff --git a/fs/namespace.c b/fs/namespace.c
index 5585623..9211da4 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1509,7 +1509,7 @@
 	return new_ns;
 }
 
-struct mnt_namespace *copy_mnt_ns(int flags, struct mnt_namespace *ns,
+struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns,
 		struct fs_struct *new_fs)
 {
 	struct mnt_namespace *new_ns;