diff --git a/fs/libfs.c b/fs/libfs.c
index 09e1016..dcaf972 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -489,7 +489,8 @@
  * unique inode values later for this filesystem, then you must take care
  * to pass it an appropriate max_reserved value to avoid collisions.
  */
-int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files)
+int simple_fill_super(struct super_block *s, unsigned long magic,
+		      struct tree_descr *files)
 {
 	struct inode *inode;
 	struct dentry *root;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3428393..471e1ff 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2388,7 +2388,7 @@
 extern const struct inode_operations simple_dir_inode_operations;
 struct tree_descr { char *name; const struct file_operations *ops; int mode; };
 struct dentry *d_alloc_name(struct dentry *, const char *);
-extern int simple_fill_super(struct super_block *, int, struct tree_descr *);
+extern int simple_fill_super(struct super_block *, unsigned long, struct tree_descr *);
 extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
 extern void simple_release_fs(struct vfsmount **mount, int *count);