diff --git a/CHANGELOG.md b/CHANGELOG.md
index e20b305fd..6a86b02ab 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@ ChangeLog (Release Notes)
 unreleased
 ----------
 * l10n
+* ユーザビリティの向上
 
 2520 (2017/08/30)
 -----------------
diff --git a/src/web/app/mobile/tags/ui-nav.tag b/src/web/app/mobile/tags/ui-nav.tag
index 76c43ade6..34235ba4f 100644
--- a/src/web/app/mobile/tags/ui-nav.tag
+++ b/src/web/app/mobile/tags/ui-nav.tag
@@ -44,6 +44,7 @@
 				width 240px
 				height 100%
 				overflow auto
+				-webkit-overflow-scrolling touch
 				color #777
 				background #fff