diff --git a/.github/workflows/DNS.yml b/.github/workflows/DNS.yml
index 781c13fb..e6319c09 100644
--- a/.github/workflows/DNS.yml
+++ b/.github/workflows/DNS.yml
@@ -69,13 +69,11 @@ jobs:
     - uses: actions/checkout@v4
     - name: Clone acmetest
       run: cd .. && git clone --depth=1 https://github.com/acmesh-official/acmetest.git  && cp -r acme.sh acmetest/
-    - name: Ensure oathtool in test container
+    - name: Install oathtool in test container
       run: |
         cd ../acmetest
-        # Add oathtool installation to acmetest Dockerfile if it exists
-        if [ -f Dockerfile ]; then
-          sed -i 's/tzdata/tzdata oath-toolkit-oathtool/g' Dockerfile
-        fi
+        # Modify letest.sh to install oathtool at runtime  
+        sed -i '/TEST_LOCAL skip setup/a apt-get update -qq && apt-get install -y -qq oathtool > /dev/null 2>&1 || true' letest.sh
     - name: Set env file
       run: |
         cd ../acmetest