diff --git a/qutebrowser/widgets/statusbar/_url.py b/qutebrowser/widgets/statusbar/_url.py
index 1f107a7e8..25fdbd238 100644
--- a/qutebrowser/widgets/statusbar/_url.py
+++ b/qutebrowser/widgets/statusbar/_url.py
@@ -101,6 +101,7 @@ class Url(TextBase):
 
     @pyqtSlot('QNetworkReply*', 'QList<QSslError>')
     def on_ssl_errors(self, _reply, _errors):
+        """Set a flag to get a warning when there were SSL errors."""
         self._ssl_errors = True
 
     @pyqtSlot(bool)