diff --git a/qutebrowser/config/config.py b/qutebrowser/config/config.py
index 8f34b6e44..4ad00fec4 100644
--- a/qutebrowser/config/config.py
+++ b/qutebrowser/config/config.py
@@ -253,7 +253,10 @@ class Config(QObject):
         self.changed.connect(_render_stylesheet.cache_clear)
         self._mutables = {}
         self._yaml = yaml_config
+        self._init_values()
 
+    def _init_values(self):
+        """Populate the self._values dict."""
         self._values = {}
         for name, opt in configdata.DATA.items():
             self._values[name] = configutils.Values(opt)
diff --git a/tests/unit/completion/test_models.py b/tests/unit/completion/test_models.py
index ff9a24112..32e6920fe 100644
--- a/tests/unit/completion/test_models.py
+++ b/tests/unit/completion/test_models.py
@@ -80,9 +80,9 @@ def cmdutils_stub(monkeypatch, stubs):
 
 
 @pytest.fixture()
-def configdata_stub(monkeypatch, configdata_init):
+def configdata_stub(config_stub, monkeypatch, configdata_init):
     """Patch the configdata module to provide fake data."""
-    return monkeypatch.setattr(configdata, 'DATA', collections.OrderedDict([
+    monkeypatch.setattr(configdata, 'DATA', collections.OrderedDict([
         ('aliases', configdata.Option(
             name='aliases',
             description='Aliases for commands.',
@@ -132,6 +132,7 @@ def configdata_stub(monkeypatch, configdata_init):
             backends=[],
             raw_backends=None)),
     ]))
+    config_stub._init_values()
 
 
 @pytest.fixture