diff --git a/tests/integration/test_main.py b/tests/integration/test_main.py
index 27acab5..7aee3b8 100644
--- a/tests/integration/test_main.py
+++ b/tests/integration/test_main.py
@@ -9,6 +9,10 @@ import pytest
 from flake8 import utils
 from flake8.main import cli
 
+from flake8.options import config
+config.ADDITIONAL_LOCATIONS = ()
+config.ADDITIONAL_CANDIDATES = ()
+
 
 def test_diff_option(tmpdir, capsys):
     """Ensure that `flake8 --diff` works."""
diff --git a/tests/unit/test_options_config.py b/tests/unit/test_options_config.py
index 75bfac5..b89daf3 100644
--- a/tests/unit/test_options_config.py
+++ b/tests/unit/test_options_config.py
@@ -8,6 +8,8 @@ from flake8.options.manager import OptionManager
 
 
 def test_config_not_found_returns_none(tmp_path):
+    config.ADDITIONAL_LOCATIONS = ()
+    config.ADDITIONAL_CANDIDATES = ()
     assert config._find_config_file(str(tmp_path)) is None