diff --git a/regexp.txt b/regexp.txt
index 9a3efee..5de222a 100644
--- a/regexp.txt
+++ b/regexp.txt
@@ -1,3 +1,4 @@
 第\s*(\d+)\s*巻
 (?i)vo?l?u?m?e?[.\s]*(\d+)
+(?i)cha?p?t?e?r?[.\s]*(\d+)
 (\d+)\D*$