diff --git a/tests/conftest.py b/tests/conftest.py
index 06d66a75..221eb036 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -44,7 +44,9 @@ def load_plugin(nonebug_init: None) -> set["Plugin"]:
 
 
 @pytest.fixture
-async def app(app: App, tmp_path: Path, mocker: MockerFixture):
+async def app(
+    app: App, tmp_path: Path, mocker: MockerFixture, monkeypatch: pytest.MonkeyPatch
+):
     from src.plugins.github import plugin_config
     from src.providers.utils import dump_json5
 
@@ -98,6 +100,7 @@ async def app(app: App, tmp_path: Path, mocker: MockerFixture):
     mocker.patch.object(
         plugin_config, "github_step_summary", tmp_path / "step_summary.txt"
     )
+    monkeypatch.setenv("GITHUB_STEP_SUMMARY", str(tmp_path / "step_summary.md"))
 
     yield app