diff --git a/spyder/plugins/maininterpreter/tests/test_confpage.py b/spyder/plugins/maininterpreter/tests/test_confpage.py
index 392b54bbdf7..f2fd4a885ed 100644
--- a/spyder/plugins/maininterpreter/tests/test_confpage.py
+++ b/spyder/plugins/maininterpreter/tests/test_confpage.py
@@ -12,8 +12,6 @@
 # Local imports
 from spyder.api.plugins import Plugins
 from spyder.api.plugin_registration.registry import PLUGIN_REGISTRY
-from spyder.config.manager import CONF
-from spyder.plugins.preferences.api import PreferencePages
 from spyder.plugins.maininterpreter.plugin import MainInterpreter
 from spyder.plugins.preferences.tests.conftest import MainWindowMock
 from spyder.utils.conda import get_list_conda_envs
@@ -22,7 +20,7 @@
 
 # Get envs to show them in the Main interpreter page. This is actually
 # done in a thread in the InterpreterStatus widget.
-# We also recording the time needed to get them to compare it with the
+# We're also recording the time needed to get them to compare it with the
 # loading time of that config page.
 t0 = time.time()
 get_list_conda_envs()
@@ -31,14 +29,11 @@
 
 
 def test_load_time(qtbot):
-    from spyder.plugins.maininterpreter.confpage import (
-        MainInterpreterConfigPage)
-
     # Create Preferences dialog
     main = MainWindowMock()
     preferences = main.get_plugin(Plugins.Preferences)
 
-    main_interpreter = PLUGIN_REGISTRY.register_plugin(main, MainInterpreter)
+    PLUGIN_REGISTRY.register_plugin(main, MainInterpreter)
 
     # Create page and measure time to do it
     t0 = time.time()
diff --git a/spyder/plugins/preferences/plugin.py b/spyder/plugins/preferences/plugin.py
index eb914c54814..43821ab0df1 100644
--- a/spyder/plugins/preferences/plugin.py
+++ b/spyder/plugins/preferences/plugin.py
@@ -310,7 +310,6 @@ def on_application_available(self):
 
     @on_plugin_teardown(plugin=Plugins.MainMenu)
     def on_main_menu_teardown(self):
-        container = self.get_container()
         main_menu = self.get_plugin(Plugins.MainMenu)
 
         main_menu.remove_item_from_application_menu(
@@ -325,7 +324,6 @@ def on_main_menu_teardown(self):
 
     @on_plugin_teardown(plugin=Plugins.Toolbar)
     def on_toolbar_teardown(self):
-        container = self.get_container()
         toolbar = self.get_plugin(Plugins.Toolbar)
         toolbar.remove_item_from_application_toolbar(
             PreferencesActions.Show,
diff --git a/spyder/plugins/preferences/tests/conftest.py b/spyder/plugins/preferences/tests/conftest.py
index 1e93f48d5be..496b3bbad80 100644
--- a/spyder/plugins/preferences/tests/conftest.py
+++ b/spyder/plugins/preferences/tests/conftest.py
@@ -10,7 +10,6 @@
 """
 
 import types
-
 from unittest.mock import Mock, MagicMock
 
 # Third party imports