diff --git a/.gitea/workflows/pr-check.yaml b/.gitea/workflows/pr-check.yaml
index 53262aa..26d00dc 100644
--- a/.gitea/workflows/pr-check.yaml
+++ b/.gitea/workflows/pr-check.yaml
@@ -45,14 +45,28 @@ jobs:
       - name: 1. Commit Message Check
         shell: sh
         run: |
+          set -eu
           echo "Checking commit messages for [AC-...] or [TASK-...] (range: refs/remotes/origin/main..HEAD)"
-          # refs/remotes/origin/main is fetched in the checkout step
-          git log --no-merges --format=%B refs/remotes/origin/main..HEAD | cat
-          
-          if git log --no-merges --format=%B refs/remotes/origin/main..HEAD | grep -Eq '\[(AC|TASK)-'; then
+
+          range="refs/remotes/origin/main..HEAD"
+
+          # Ignore tool-generated merge commits and filter out merge titles
+          msgs="$(git log --format=%B --no-merges "$range" || true)"
+
+          if [ -z "${msgs}" ]; then
+            echo "WARNING: No non-merge commits found in range ${range}. Skipping commit message gate."
+            exit 0
+          fi
+
+          echo "$msgs" | cat
+
+          # Drop lines like "Merge branch ..." just in case
+          filtered="$(echo "$msgs" | grep -Ev '^(Merge( branch)? |Merge pull request )' || true)"
+
+          if echo "$filtered" | grep -Eq '\[(AC|TASK)-'; then
             echo "OK: Found [AC-...] or [TASK-...] in PR commits"
           else
-            echo "ERROR: At least one commit message in the PR must contain [AC-...] or [TASK-...]"
+            echo "ERROR: At least one non-merge commit message in the PR must contain [AC-...] or [TASK-...]"
             exit 1
           fi