diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index 9f74a62..e65a019 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -162,9 +162,9 @@
 extern const struct file_operations ext2_xip_file_operations;
 
 /* inode.c */
-extern struct address_space_operations ext2_aops;
-extern struct address_space_operations ext2_aops_xip;
-extern struct address_space_operations ext2_nobh_aops;
+extern const struct address_space_operations ext2_aops;
+extern const struct address_space_operations ext2_aops_xip;
+extern const struct address_space_operations ext2_nobh_aops;
 
 /* namei.c */
 extern struct inode_operations ext2_dir_inode_operations;