diff --git a/.github/workflows/push.yml b/.github/workflows/push.yml
index 5bdde17..fad50dc 100644
--- a/.github/workflows/push.yml
+++ b/.github/workflows/push.yml
@@ -9,7 +9,7 @@ jobs:
     - uses: actions/checkout@master
     - name: Dump GitHub context
       env:
-        GITHUB_CONTEXT_COMMIT_MSG: ${{ github.event.commits }}
+        GITHUB_CONTEXT_COMMIT_MSG: ${{ toJson(github.event.commits) }}
         GITHUB_CONTEXT_COMMIT_MSG_COND: ${{ contains(github.event.commits, '[skip ci]') }}
         GITHUB_CONTEXT: ${{ toJson(github) }}
       run: |