diff --git a/.github/workflows/agent-pr-ready-automerge.yml b/.github/workflows/agent-pr-ready-automerge.yml
index ece4c3b2..001c7677 100644
--- a/.github/workflows/agent-pr-ready-automerge.yml
+++ b/.github/workflows/agent-pr-ready-automerge.yml
@@ -49,4 +49,9 @@ jobs:
           node-version: 24
           package-manager-cache: false
       - name: Mark Ready and arm auto-merge
+        env:
+          # Explicit `github.token` — the built-in GITHUB_TOKEN env is not
+          # guaranteed to be injected on every event path; passing it via the
+          # documented context is the robust form.
+          GITHUB_TOKEN: ${{ github.token }}
         run: node scripts/github-pr-automerge.mjs --pr "${{ github.event.pull_request.number }}"