diff --git a/.gitea/workflows/ci.yaml b/.gitea/workflows/ci.yaml
index 5e4b96f..8b29693 100644
--- a/.gitea/workflows/ci.yaml
+++ b/.gitea/workflows/ci.yaml
@@ -31,6 +31,17 @@ jobs:
           echo "deb https://mirror.nju.edu.cn/ubuntu/ focal-updates main restricted universe multiverse" >> /etc/apt/sources.list
           echo "deb https://mirror.nju.edu.cn/ubuntu/ focal-backports main restricted universe multiverse" >> /etc/apt/sources.list
           echo "deb https://mirror.nju.edu.cn/ubuntu/ focal-security main restricted universe multiverse" >> /etc/apt/sources.list
+
+      - name: Add missing GPG keys for NJU mirror
+        run: |
+          # 添加公钥 3B4FE6ACC0B21F32
+          curl -fsSL https://keyserver.ubuntu.com/pks/lookup?op=get&search=0x3B4FE6ACC0B21F32 | sudo tee /etc/apt/trusted.gpg.d/nju-archive-key.asc
+
+          # 添加公钥 871920D1991BC93C
+          curl -fsSL https://keyserver.ubuntu.com/pks/lookup?op=get&search=0x871920D1991BC93C | sudo tee /etc/apt/trusted.gpg.d/nju-archive-key.asc
+
+      - name: Install gnupg
+        run: |
           apt-get update --allow-unauthenticated --ignore-missing
           apt-get install --allow-unauthenticated -y gnupg