diff --git a/local-tool/installer/windows/visiona-local.iss b/local-tool/installer/windows/visiona-local.iss
index 0e5d876..97adac1 100644
--- a/local-tool/installer/windows/visiona-local.iss
+++ b/local-tool/installer/windows/visiona-local.iss
@@ -48,7 +48,13 @@ MinVersion=10.0.17763
 
 [Languages]
 Name: "english"; MessagesFile: "compiler:Default.isl"
-Name: "tradchinese"; MessagesFile: "compiler:Languages\ChineseTraditional.isl"
+; 繁體中文語系：Inno Setup 6.3+ 官方只內建簡體中文（ChineseSimplified.isl）
+; 繁體中文需額外從 https://jrsoftware.org/files/istrans/ 下載放到 Languages/
+; 若存在則載入，不存在就只用英文（透過 -d 或環境變數 override 也可）
+; 使用 /DWITH_TRAD_CHINESE=1 並確認 Languages\ChineseTraditional.isl 存在才啟用
+#ifdef WITH_TRAD_CHINESE
+  Name: "tradchinese"; MessagesFile: "compiler:Languages\ChineseTraditional.isl"
+#endif
 
 [Tasks]
 Name: "desktopicon"; Description: "{cm:CreateDesktopIcon}"; GroupDescription: "{cm:AdditionalIcons}"; Flags: unchecked