diff --git a/tests/test_pr_review_merge_scheduler.py b/tests/test_pr_review_merge_scheduler.py
index 3a16137..d72be85 100644
--- a/tests/test_pr_review_merge_scheduler.py
+++ b/tests/test_pr_review_merge_scheduler.py
@@ -1,24 +1,54 @@
+import runpy
 import sys
 from pathlib import Path
+from unittest.mock import MagicMock, patch
+
 import pytest
 
 sys.path.insert(0, str(Path(__file__).parent.parent / "scripts" / "ci"))
 import pr_review_merge_scheduler
 
+
 def test_split_repo_success():
     assert pr_review_merge_scheduler.split_repo("owner/repo") == ("owner", "repo")
 
+
 def test_split_repo_success_multiple_slashes():
     assert pr_review_merge_scheduler.split_repo("owner/repo/extra") == ("owner", "repo/extra")
 
+
 def test_split_repo_invalid():
     with pytest.raises(ValueError, match="repo must be owner/name, got 'invalid'"):
         pr_review_merge_scheduler.split_repo("invalid")
 
+
 def test_split_repo_empty_owner():
     with pytest.raises(ValueError, match="repo must be owner/name, got '/repo'"):
         pr_review_merge_scheduler.split_repo("/repo")
 
+
 def test_split_repo_empty_repo():
     with pytest.raises(ValueError, match="repo must be owner/name, got 'owner/'"):
         pr_review_merge_scheduler.split_repo("owner/")
+
+
+def test_error_path(capsys, monkeypatch):
+    monkeypatch.setattr("sys.argv", ["pr_review_merge_scheduler.py", "--repo", "owner/repo"])
+
+    with patch("subprocess.run") as mock_run:
+        mock_process = MagicMock()
+        mock_process.returncode = 1
+        mock_process.stderr = "fake error message"
+        mock_run.return_value = mock_process
+
+        with pytest.raises(SystemExit, match="1") as excinfo:
+            runpy.run_path(
+                str(Path(__file__).parent.parent / "scripts" / "ci" / "pr_review_merge_scheduler.py"),
+                run_name="__main__",
+            )
+
+        assert excinfo.value.code == 1
+
+    captured = capsys.readouterr()
+    assert "Command failed" in captured.err
+    assert "fake error message" in captured.err