diff --git a/tests/test_opencode_review_normalize_output.py b/tests/test_opencode_review_normalize_output.py
new file mode 100644
index 0000000..156d0ca
--- /dev/null
+++ b/tests/test_opencode_review_normalize_output.py
@@ -0,0 +1,22 @@
+from unittest.mock import patch
+
+from scripts.ci import opencode_review_normalize_output
+
+def test_main_oserror_on_read(capsys):
+    argv = [
+        "opencode_review_normalize_output.py",
+        "expected_sha",
+        "123",
+        "1",
+        "nonexistent_file.json",
+    ]
+
+    with patch("scripts.ci.opencode_review_normalize_output.Path.read_text") as mock_read_text:
+        mock_read_text.side_effect = OSError("mocked error")
+
+        return_code = opencode_review_normalize_output.main(argv)
+
+    assert return_code == 65
+
+    captured = capsys.readouterr()
+    assert "cannot read OpenCode output file: mocked error" in captured.err