diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 91b4292..2e5ab4c 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -66,9 +66,13 @@ jobs:
             exit 1
           }
           sudo apt-get update > /tmp/apt.log 2>&1 || annotate "apt 更新失败" /tmp/apt.log
+          # runner 自带字体极少。界面文案是中文，缺 CJK 字体会渲染成豆腐块，
+          # 文本版式测量也会跟着偏，断言量到的就不是真实排版。
           sudo apt-get install -y xvfb libnss3 libatk1.0-0t64 libatk-bridge2.0-0t64 \
-            libcups2t64 libgbm1 libasound2t64 libgtk-3-0t64 >> /tmp/apt.log 2>&1 \
+            libcups2t64 libgbm1 libasound2t64 libgtk-3-0t64 \
+            fonts-liberation fonts-noto-core fonts-noto-cjk >> /tmp/apt.log 2>&1 \
             || annotate "运行库安装失败" /tmp/apt.log
+          fc-cache -f > /dev/null 2>&1 || true
           # runner 上的 chrome-sandbox 拿不到 root:root 4755，SUID 沙箱起不来。
           # 只在 CI 关沙箱，不要把这个开关带进构建产物。
           for suite in startup download cover annotation reader-features library-notes ai-scope; do