diff --git a/app/src/main/res/values-ja/strings.xml b/app/src/main/res/values-ja/strings.xml
index 690f68931..1cd69d356 100644
--- a/app/src/main/res/values-ja/strings.xml
+++ b/app/src/main/res/values-ja/strings.xml
@@ -67,7 +67,6 @@
     <string name="debug_version_fmt">Version: <xliff:g id="version">%s</xliff:g></string>
     <string name="about_title_fmt">About <xliff:g id="app_name">%s</xliff:g></string>
     <string name="app_license">Copylefted libre software, licensed GPLv3+</string>
-    <string name="app_copyright_old"></string>
     <string name="app_resources">Libre third-party resources: <xliff:g id="app_resources_list">%s</xliff:g></string>
     <string name="about">Catimaについて</string>
     <string name="importOptionApplicationButton">外部のアプリを使う</string>