diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index 15c866f1a1fdacbf53c08652cf6eefeaf303f790..4f5418be0590ed6d484fd628a31fc65c9c7bea71 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -197,7 +197,7 @@ isofs_hashi_common(struct dentry *dentry, struct qstr *qstr, int ms)
 	hash = init_name_hash();
 	while (len--) {
 		c = tolower(*name++);
-		hash = partial_name_hash(tolower(c), hash);
+		hash = partial_name_hash(c, hash);
 	}
 	qstr->hash = end_name_hash(hash);