diff --git a/tests/test_cliutil.py b/tests/test_cliutil.py
index e8a386775a8dbdfb8f5295df827ba3951b56581c..08cddf36c92ef980a362624b2451df9655fba289 100644
--- a/tests/test_cliutil.py
+++ b/tests/test_cliutil.py
@@ -91,6 +91,9 @@ def test_excepthook_traceback(caplog):
     assert caplog.records
     assert caplog.records[-1].message == ''.join(traceback.format_exception(*args))
 
+def test_is_main_script():
+    assert not cliutil.is_main_script()
+
 @pytest.mark.parametrize('arg,expected', [
     ('debug', logging.DEBUG),
     ('info', logging.INFO),