diff --git a/qutebrowser/config/configcache.py b/qutebrowser/config/configcache.py
index a421ba85c..15f343478 100644
--- a/qutebrowser/config/configcache.py
+++ b/qutebrowser/config/configcache.py
@@ -46,7 +46,9 @@ class ConfigCache:
             self._cache[attr] = config.instance.get(attr)
 
     def __getitem__(self, attr: str) -> typing.Any:
-        if attr not in self._cache:
+        try:
+            return self._cache[attr]
+        except KeyError:
             assert not config.instance.get_opt(attr).supports_pattern
             self._cache[attr] = config.instance.get(attr)
-        return self._cache[attr]
+            return self._cache[attr]