diff --git a/src/locales/ja/translation.json b/src/locales/ja/translation.json
index 143267bb..5c6ca96f 100644
--- a/src/locales/ja/translation.json
+++ b/src/locales/ja/translation.json
@@ -173,7 +173,7 @@
   "GeoJSON URL": "GeoJSON URL",
   "GeoJSON": "GeoJSON",
   "Cluster": "クラスタ",
-  "Tile Size": "__STRING_NOT_TRANSLATED__",
+  "Tile Size": "タイルサイズ",
   "Encoding": "エンコーディング",
   "Error:": "エラー:",
   "MapTiler Access Token": "MapTiler アクセストークン",