diff --git a/docs/translations-needed.md b/docs/translations-needed.md
index 8b1f0a3e1..bd0c718ba 100644
--- a/docs/translations-needed.md
+++ b/docs/translations-needed.md
@@ -1051,12 +1051,8 @@ This default value is hardcoded as a default to the localize method in the SeekB
 | vi.json (missing 3)     | Seek to live, currently behind live                                                 |
 |                         | Seek to live, currently playing live                                                |
 |                         | {1} is loading.                                                                     |
-| zh-CN.json (missing 4)  | Seek to live, currently behind live                                                 |
-|                         | Seek to live, currently playing live                                                |
-|                         | progress bar timing: currentTime={1} duration={2}                                   |
-|                         | {1} is loading.                                                                     |
-| zh-TW.json (missing 4)  | Seek to live, currently behind live                                                 |
-|                         | Seek to live, currently playing live                                                |
-|                         | progress bar timing: currentTime={1} duration={2}                                   |
-|                         | {1} is loading.                                                                     |
+| zh-CN.json (Complete)   |                                                                                     |
+| zh-Hans.json (Complete) |                                                                                     |
+| zh-Hant.json (Complete) |                                                                                     |
+| zh-TW.json (Complete)   |                                                                                     |
 <!-- END langtable -->
diff --git a/lang/zh-CN.json b/lang/zh-CN.json
index 67d11f92e..76f3d2615 100644
--- a/lang/zh-CN.json
+++ b/lang/zh-CN.json
@@ -79,5 +79,9 @@
   "Done": "完成",
   "Caption Settings Dialog": "字幕设定视窗",
   "Beginning of dialog window. Escape will cancel and close the window.": "开始对话视窗。离开会取消及关闭视窗",
-  "End of dialog window.": "结束对话视窗"
+  "End of dialog window.": "结束对话视窗",
+  "Seek to live, currently behind live": "试图直播，当前延时播放",
+  "Seek to live, currently playing live": "试图直播，当前实时播放",
+  "progress bar timing: currentTime={1} duration={2}": "{1}/{2}",
+  "{1} is loading.": "正在加载 {1}。"
 }
diff --git a/lang/zh-TW.json b/lang/zh-TW.json
index 5a5a293ce..c2cd0f895 100644
--- a/lang/zh-TW.json
+++ b/lang/zh-TW.json
@@ -79,5 +79,9 @@
   "Done": "完成",
   "Caption Settings Dialog": "字幕設定視窗",
   "Beginning of dialog window. Escape will cancel and close the window.": "開始對話視窗。離開會取消及關閉視窗",
-  "End of dialog window.": "結束對話視窗"
+  "End of dialog window.": "結束對話視窗",
+  "Seek to live, currently behind live": "試圖直播，目前延時播放",
+  "Seek to live, currently playing live": "試圖直播，目前即時播放",
+  "progress bar timing: currentTime={1} duration={2}": "{1}/{2}",
+  "{1} is loading.": "{1} 正在載入。"
 }
diff --git a/package.json b/package.json
index 0a102afb0..4fd31b47b 100644
--- a/package.json
+++ b/package.json
@@ -20,7 +20,7 @@
     "sandbox": "node build/sandbox.js",
     "prestart": "npm-run-all sandbox",
     "start": "npm-run-all -p watch karma-server",
-    "clean": "shx rm -rf ./dist ./test/dist ./docs/api",
+    "clean": "shx rm -rf ./dist ./test/dist ./docs/api ./lang/zh-Han*.json",
     "postclean": "shx mkdir -p ./dist/lang ./test/dist",
     "changelog": "conventional-changelog -p videojs -i CHANGELOG.md -s",
     "build": "npm-run-all build-dev minify copy zip",
@@ -38,11 +38,11 @@
     "postbuild:css:cdn": "postcss --verbose --config postcss.config.js -d dist/alt dist/alt/video-js-cdn.css",
     "build:css:default": "sass --no-source-map src/css/vjs.scss dist/video-js.css",
     "postbuild:css:default": "postcss --verbose --config postcss.config.js -d dist/ dist/video-js.css",
-    "build:lang": "npm-run-all build:lang:*",
-    "build:lang:chinese-s": "shx cp lang/zh-CN.json lang/zh-Hans.json",
-    "build:lang:chinese-t": "shx cp lang/zh-TW.json lang/zh-Hant.json",
-    "build:lang:js": "vjslang --dir dist/lang",
-    "build:lang:copy": "shx cp -R lang/* dist/lang/",
+    "prebuild:lang": "npm-run-all -s prebuild:lang:*",
+    "prebuild:lang:chinese-s": "shx cp lang/zh-CN.json lang/zh-Hans.json",
+    "prebuild:lang:chinese-t": "shx cp lang/zh-TW.json lang/zh-Hant.json",
+    "build:lang": "vjslang --dir dist/lang",
+    "postbuild:lang": "shx cp -R lang/* dist/lang/",
     "minify": "npm-run-all minify:*",
     "minify:js": "babel-node build/minify.js",
     "minify:css": "npm-run-all minify:css:*",