diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index 11035ac..9f74a62 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -154,12 +154,12 @@
  */
 
 /* dir.c */
-extern struct file_operations ext2_dir_operations;
+extern const struct file_operations ext2_dir_operations;
 
 /* file.c */
 extern struct inode_operations ext2_file_inode_operations;
-extern struct file_operations ext2_file_operations;
-extern struct file_operations ext2_xip_file_operations;
+extern const struct file_operations ext2_file_operations;
+extern const struct file_operations ext2_xip_file_operations;
 
 /* inode.c */
 extern struct address_space_operations ext2_aops;