diff --git a/tests/clientlib_test.py b/tests/clientlib_test.py
index 6cf42a9f3..6f5a1e45c 100644
--- a/tests/clientlib_test.py
+++ b/tests/clientlib_test.py
@@ -228,7 +228,7 @@ def test_warn_mutable_rev_invalid(caplog, rev):
             'Mutable references are never updated after first install and are '
             'not supported.  '
             'See https://pre-commit.com/#using-the-latest-version-for-a-repository '  # noqa: E501
-            'for more details.'
+            'for more details. '
             'To remove this warning consider running autoupdate via: '
             '`pre-commit autoupdate --repo https://gitlab.com/pycqa/flake8`',
         ),