diff --git a/.github/workflows/treadmill-ci-test.yml b/.github/workflows/treadmill-ci-test.yml
index 1120ee3..cc46399 100644
--- a/.github/workflows/treadmill-ci-test.yml
+++ b/.github/workflows/treadmill-ci-test.yml
@@ -37,7 +37,8 @@ jobs:
 
       # Provide access to the required Treadmill secrets by running in the
       # appropriate environment (depending on the on: triggers above)
-      job-environment: ${{ github.event_name == 'pull_request' && 'treadmill-ci' || 'treadmill-ci-merged' }}
+      job-environment: ${{ github.ref == 'refs/heads/main' || github.event_name == 'merge_group' && 'treadmill-ci-merged' || 'treadmill-ci' }}
+
 
       # This workflow tests the tock-hardware-ci scripts itself, so take the
       # current GITHUB_SHA: