diff --git a/ci/Jenkinsfile.hermes-agent-image b/ci/Jenkinsfile.hermes-agent-image
index 776c34a3..c10ff9e4 100644
--- a/ci/Jenkinsfile.hermes-agent-image
+++ b/ci/Jenkinsfile.hermes-agent-image
@@ -329,6 +329,10 @@ spec:
         }
       }
       steps {
+        // This amd64 leg runs on its own fresh pod (titan-24), so it must check
+        // out the SCM itself before the reviewed-revision git boundary check —
+        // otherwise `git rev-parse origin/main` fails with "not a git repository".
+        checkout scm
         container('jnlp') {
           sh '''
             set -eu