diff --git a/qutebrowser/config/config.py b/qutebrowser/config/config.py
index 58359a335..846c75642 100644
--- a/qutebrowser/config/config.py
+++ b/qutebrowser/config/config.py
@@ -500,15 +500,17 @@ class ConfigContainer:
     Attributes:
         _config: The Config object.
         _prefix: The __getattr__ chain leading up to this object.
+        _confpy: If True, get values suitable for config.py.
     """
 
-    def __init__(self, config, prefix=''):
+    def __init__(self, config, confpy=False, prefix=''):
         self._config = config
         self._prefix = prefix
+        self._confpy = confpy
 
     def __repr__(self):
         return utils.get_repr(self, constructor=True, config=self._config,
-                              prefix=self._prefix)
+                              confpy=self._confpy, prefix=self._prefix)
 
     def __getattr__(self, attr):
         """Get an option or a new ConfigContainer with the added prefix.
@@ -524,9 +526,13 @@ class ConfigContainer:
 
         name = self._join(attr)
         if configdata.is_valid_prefix(name):
-            return ConfigContainer(config=self._config, prefix=name)
+            return ConfigContainer(config=self._config, confpy=self._confpy,
+                                   prefix=name)
 
-        return self._config.get(name)
+        if self._confpy:
+            return self._config.get_obj(name)
+        else:
+            return self._config.get(name)
 
     def __setattr__(self, attr, value):
         """Set the given option in the config."""
diff --git a/qutebrowser/config/configfiles.py b/qutebrowser/config/configfiles.py
index 1ac6668c8..f4ff912ae 100644
--- a/qutebrowser/config/configfiles.py
+++ b/qutebrowser/config/configfiles.py
@@ -134,7 +134,8 @@ def read_config_py(filename=None):
         if not os.path.exists(filename):
             return None
 
-    api = ConfigAPI(config.instance, config.key_instance, config.val)
+    container = config.ConfigContainer(config.instance, confpy=True)
+    api = ConfigAPI(config.instance, config.key_instance, container)
     module = types.ModuleType('config')
     module.config = api
     module.c = api.val
@@ -145,6 +146,8 @@ def read_config_py(filename=None):
     code = compile(source, filename, 'exec')
     exec(code, module.__dict__)
 
+    config.instance.update_mutables()
+
     return api
 
 
diff --git a/tests/unit/config/test_config.py b/tests/unit/config/test_config.py
index 9ddf5d373..99a57d479 100644
--- a/tests/unit/config/test_config.py
+++ b/tests/unit/config/test_config.py
@@ -777,8 +777,14 @@ class TestContainer:
         new_container = new_container.favicons
         assert new_container._prefix == 'tabs.favicons'
 
-    def test_getattr_option(self, container):
-        assert container.tabs.show == 'always'
+    @pytest.mark.parametrize('confpy, expected', [
+        (True, 'rgb'),
+        (False, QColor.Rgb),
+    ])
+    def test_getattr_option(self, container, confpy, expected):
+        container._confpy = confpy
+        # Use an option with a to_py() so we can check the conversion.
+        assert container.colors.downloads.system.fg == expected
 
     def test_getattr_invalid(self, container):
         with pytest.raises(configexc.NoOptionError) as excinfo:
diff --git a/tests/unit/config/test_configfiles.py b/tests/unit/config/test_configfiles.py
index d077e9918..c598f4acb 100644
--- a/tests/unit/config/test_configfiles.py
+++ b/tests/unit/config/test_configfiles.py
@@ -161,6 +161,11 @@ class TestConfigPy:
         expected = {'normal': {'o': None}}
         assert config.instance._values['bindings.commands'] == expected
 
+    def test_mutating(self, confpy):
+        confpy.write('c.aliases["foo"] = "message-info foo"')
+        configfiles.read_config_py(confpy.filename)
+        assert config.instance._values['aliases']['foo'] == 'message-info foo'
+
     def test_reading_default_location(self, config_tmpdir):
         (config_tmpdir / 'config.py').write_text(
             'c.colors.hints.bg = "red"', 'utf-8')