diff --git a/actions.json b/actions.json
index 3e89d2b..7bf11ba 100644
--- a/actions.json
+++ b/actions.json
@@ -53,6 +53,21 @@
         "actions/checkout"
       ]
     },
+    {
+      "addLabels": [
+        "renovate/automerge",
+        "renovate/github-action"
+      ],
+      "allowedVersions": "<22.0.0",
+      "automerge": true,
+      "enabled": true,
+      "matchManagers": [
+        "github-actions"
+      ],
+      "matchPackageNames": [
+        "DavidAnson/markdownlint-cli2-action"
+      ]
+    },
     {
       "addLabels": [
         "renovate/automerge",