diff --git a/tests/unit/browser/test_adblock.py b/tests/unit/browser/test_adblock.py
index 02caca581..afc400d1d 100644
--- a/tests/unit/browser/test_adblock.py
+++ b/tests/unit/browser/test_adblock.py
@@ -97,7 +97,7 @@ class TestIsWhitelistedHost:
     """Test function adblock.is_whitelisted_host."""
 
     def test_without_option(self, config_stub):
-        """Option host-blocking-whitelist does not exist"""
+        """Option host-blocking-whitelist does not exist."""
         config_stub.data = {'content': {}}
         with pytest.raises(configexc.NoOptionError):
             adblock.is_whitelisted_host('qutebrowser.org')