diff --git a/.github/actions/prose-gate/action.yml b/.github/actions/prose-gate/action.yml
index e8f9fbe6..edca233c 100644
--- a/.github/actions/prose-gate/action.yml
+++ b/.github/actions/prose-gate/action.yml
@@ -23,7 +23,19 @@ runs:
         # Check the base resolves before scanning, so an empty or absent ref fails naming itself.
         # Unresolvable, the run would report the repository's whole backlog against this change.
         # A shallow checkout is the usual cause, so the caller fetches full history.
-        if ! git rev-parse --verify --quiet "$BASE^{commit}" >/dev/null; then
+        # A base that is a freshly created merge commit can still lag GitHub's own replication, so retry with backoff before failing rather than treat that lag as a gate failure.
+        resolved=false
+        for delay in 0 2 4 8 15 30; do
+          if [ "$delay" -gt 0 ]; then
+            sleep "$delay"
+            git fetch --quiet origin "$BASE" 2>/dev/null || true
+          fi
+          if git rev-parse --verify --quiet "$BASE^{commit}" >/dev/null; then
+            resolved=true
+            break
+          fi
+        done
+        if ! "$resolved"; then
           echo "::error::Diff base '$BASE' does not resolve in this checkout." >&2
           echo "::error::Check the ref name and that the job checks out with fetch-depth 0." >&2
           exit 1