diff --git a/tests/test_docs.py b/tests/test_docs.py
index 1d659d1..87b685e 100644
--- a/tests/test_docs.py
+++ b/tests/test_docs.py
@@ -24,4 +24,4 @@ def test_commands_are_documented(documented_commands, command):
 
 @pytest.mark.parametrize("command", cli.cli.commands.values())
 def test_commands_have_docstrings(command):
-    assert command.__doc__, '{} is missing a docstring'.format(command)
+    assert command.__doc__, "{} is missing a docstring".format(command)