diff --git a/fs/dcache.c b/fs/dcache.c
index ad25c4c..129a357 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2131,7 +2131,7 @@
  */
 void dentry_update_name_case(struct dentry *dentry, struct qstr *name)
 {
-	BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex));
+	BUG_ON(!mutex_is_locked(&dentry->d_parent->d_inode->i_mutex));
 	BUG_ON(dentry->d_name.len != name->len); /* d_lookup gives this */
 
 	spin_lock(&dentry->d_lock);