diff --git a/test/formats/common.py b/test/formats/common.py
index 52134c3f8..4e1900018 100644
--- a/test/formats/common.py
+++ b/test/formats/common.py
@@ -201,7 +201,7 @@ class CommonTests:
 
         def setUp(self):
             super().setUp()
-            config.setting = settings.copy()
+            self.set_config_values(settings)
             if self.testfile:
                 _name, self.testfile_ext = os.path.splitext(self.testfile)
                 self.testfile_path = os.path.join('test', 'data', self.testfile)
diff --git a/test/picardtestcase.py b/test/picardtestcase.py
index 8c9741478..85a2b19c7 100644
--- a/test/picardtestcase.py
+++ b/test/picardtestcase.py
@@ -3,7 +3,7 @@
 # Picard, the next-generation MusicBrainz tagger
 #
 # Copyright (C) 2018 Wieland Hoffmann
-# Copyright (C) 2019 Philipp Wolfer
+# Copyright (C) 2019-2020 Philipp Wolfer
 # Copyright (C) 2020 Laurent Monin
 #
 # This program is free software; you can redistribute it and/or
@@ -29,7 +29,9 @@ from tempfile import (
     mkdtemp,
     mkstemp,
 )
+import threading
 import unittest
+from unittest.mock import Mock
 
 from PyQt5 import QtCore
 
@@ -72,7 +74,28 @@ class PicardTestCase(unittest.TestCase):
         self.tagger = FakeTagger()
         QtCore.QObject.tagger = self.tagger
         self.addCleanup(self.tagger.run_cleanup)
-        config.setting = {}
+        self.init_config()
+
+    @staticmethod
+    def init_config():
+        fake_config = Mock()
+        fake_config.setting = {}
+        fake_config.persist = {}
+        # Make config object available to current thread
+        config._thread_configs[threading.get_ident()] = fake_config
+        # Make config object available for legacy use
+        config.config = fake_config
+        config.setting = fake_config.setting
+        config.persist = fake_config.persist
+
+    @staticmethod
+    def set_config_values(setting=None, persist=None):
+        if setting:
+            for key, value in setting.items():
+                config.config.setting[key] = value
+        if persist:
+            for key, value in persist.items():
+                config.config.persist[key] = value
 
     def mktmpdir(self, ignore_errors=False):
         tmpdir = mkdtemp(suffix=self.__class__.__name__)
diff --git a/test/test_acoustid.py b/test/test_acoustid.py
index 36068da4f..662d5393f 100644
--- a/test/test_acoustid.py
+++ b/test/test_acoustid.py
@@ -27,7 +27,6 @@ import os
 
 from test.picardtestcase import PicardTestCase
 
-from picard import config
 from picard.acoustid.json_helpers import parse_recording
 from picard.mbjson import recording_to_metadata
 from picard.metadata import Metadata
@@ -49,7 +48,7 @@ class AcoustIDTest(PicardTestCase):
         self.init_test(self.filename)
 
     def init_test(self, filename):
-        config.setting = settings.copy()
+        self.set_config_values(settings)
         self.json_doc = None
         with open(os.path.join('test', 'data', 'ws_data', filename), encoding='utf-8') as f:
             self.json_doc = json.load(f)
diff --git a/test/test_acoustidmanager.py b/test/test_acoustidmanager.py
index ea80862d2..f52f0e07c 100644
--- a/test/test_acoustidmanager.py
+++ b/test/test_acoustidmanager.py
@@ -27,7 +27,6 @@ from unittest.mock import (
 
 from test.picardtestcase import PicardTestCase
 
-from picard import config
 from picard.acoustid.manager import AcoustIDManager
 from picard.file import File
 
@@ -55,10 +54,10 @@ def dummy_file(i):
 class AcoustIDManagerTest(PicardTestCase):
     def setUp(self):
         super().setUp()
-        config.setting = {
+        self.set_config_values({
             "clear_existing_tags": False,
             "compare_ignore_tags": []
-        }
+        })
         self.mock_api_helper = MagicMock()
         self.mock_api_helper.submit_acoustid_fingerprints = Mock(wraps=mock_succeed_submission)
         self.acoustidmanager = AcoustIDManager(self.mock_api_helper)
diff --git a/test/test_api_helpers.py b/test/test_api_helpers.py
index 72f5af50d..c00c25ab5 100644
--- a/test/test_api_helpers.py
+++ b/test/test_api_helpers.py
@@ -26,7 +26,6 @@ from unittest.mock import MagicMock
 
 from test.picardtestcase import PicardTestCase
 
-from picard import config
 from picard.webservice import WebService
 from picard.webservice.api_helpers import (
     APIHelper,
@@ -72,8 +71,9 @@ class APITest(PicardTestCase):
 class MBAPITest(PicardTestCase):
 
     def setUp(self):
+        super().setUp()
         self.config = {'server_host': "mb.org", "server_port": 443}
-        config.setting = self.config.copy()
+        self.set_config_values(self.config)
         self.ws = MagicMock(auto_spec=WebService)
         self.api = MBAPIHelper(self.ws)
 
diff --git a/test/test_file.py b/test/test_file.py
index c43a745bc..5cc37c4fa 100644
--- a/test/test_file.py
+++ b/test/test_file.py
@@ -171,7 +171,7 @@ class FileNamingTest(PicardTestCase):
     def setUp(self):
         super().setUp()
         self.file = File('/somepath/somefile.mp3')
-        config.setting = {
+        self.set_config_values({
             'ascii_filenames': False,
             'clear_existing_tags': False,
             'enabled_plugins': [],
@@ -180,7 +180,7 @@ class FileNamingTest(PicardTestCase):
             'move_files': False,
             'rename_files': False,
             'windows_compatibility': True,
-        }
+        })
         self.metadata = Metadata({
             'album': 'somealbum',
             'title': 'sometitle',
diff --git a/test/test_filesystem.py b/test/test_filesystem.py
index 91591d551..8c966a425 100644
--- a/test/test_filesystem.py
+++ b/test/test_filesystem.py
@@ -46,7 +46,7 @@ class TestFileSystem(PicardTestCase):
         super().setUp()
         self.src_directory = self.mktmpdir()
         self.tgt_directory = self.mktmpdir()
-        config.setting = settings.copy()
+        self.set_config_values(settings)
 
     def _prepare_files(self, src_rel_path='', tgt_rel_path=''):
         """Prepare src files and tgt filenames for a test."""
diff --git a/test/test_interface_colors.py b/test/test_interface_colors.py
index 83546697c..e5e43fe5b 100644
--- a/test/test_interface_colors.py
+++ b/test/test_interface_colors.py
@@ -47,7 +47,7 @@ settings = {
 class InterfaceColorsTest(PicardTestCase):
     def setUp(self):
         super().setUp()
-        config.setting = settings.copy()
+        self.set_config_values(settings)
 
     def test_interface_colors(self):
         for key in ('interface_colors', 'interface_colors_dark'):
diff --git a/test/test_mbjson.py b/test/test_mbjson.py
index c31be083f..2adbf52ff 100644
--- a/test/test_mbjson.py
+++ b/test/test_mbjson.py
@@ -64,7 +64,7 @@ class MBJSONTest(PicardTestCase):
         self.init_test(self.filename)
 
     def init_test(self, filename):
-        config.setting = settings.copy()
+        self.set_config_values(settings)
         self.json_doc = load_test_json(filename)
 
 
diff --git a/test/test_metadata.py b/test/test_metadata.py
index a322f97e0..75a86a61b 100644
--- a/test/test_metadata.py
+++ b/test/test_metadata.py
@@ -29,7 +29,6 @@ from test.picardtestcase import (
 )
 from test.test_coverart_image import create_image
 
-from picard import config
 from picard.cluster import Cluster
 from picard.coverart.image import CoverArtImage
 from picard.file import File
@@ -74,7 +73,7 @@ class CommonTests:
 
         def setUp(self):
             super().setUp()
-            config.setting = settings.copy()
+            self.set_config_values(settings)
             self.metadata = self.get_metadata_object()
             self.metadata.length = 242
             self.metadata["single1"] = "single1-value"
diff --git a/test/test_releaseversions.py b/test/test_releaseversions.py
index 1bfe33c8c..008bef06e 100644
--- a/test/test_releaseversions.py
+++ b/test/test_releaseversions.py
@@ -31,7 +31,6 @@ from test.picardtestcase import (
     load_test_json,
 )
 
-from picard import config
 from picard.i18n import setup_gettext
 from picard.releasegroup import ReleaseGroup
 
@@ -54,7 +53,7 @@ class ReleaseTest(PicardTestCase):
         setup_gettext(self.localedir, 'C')
 
     def test_1(self):
-        config.setting = settings.copy()
+        self.set_config_values(settings)
         rlist = load_test_json('release_group_2.json')
         r = ReleaseGroup(1)
         r._parse_versions(rlist)
@@ -66,7 +65,7 @@ class ReleaseTest(PicardTestCase):
                          '5 / 2009 / GB / CD / label A / cat 123 / Digipak / specialx')
 
     def test_2(self):
-        config.setting = settings.copy()
+        self.set_config_values(settings)
         rlist = load_test_json('release_group_3.json')
         r = ReleaseGroup(1)
         r._parse_versions(rlist)
@@ -76,7 +75,7 @@ class ReleaseTest(PicardTestCase):
                          '5 / 2011 / FR / CD / label A / cat 123')
 
     def test_3(self):
-        config.setting = settings.copy()
+        self.set_config_values(settings)
         rlist = load_test_json('release_group_4.json')
         r = ReleaseGroup(1)
         r._parse_versions(rlist)
diff --git a/test/test_script.py b/test/test_script.py
index 00e56315d..a719c1f0f 100644
--- a/test/test_script.py
+++ b/test/test_script.py
@@ -37,7 +37,6 @@ from unittest.mock import MagicMock
 
 from test.picardtestcase import PicardTestCase
 
-from picard import config
 from picard.cluster import Cluster
 from picard.const import DEFAULT_FILE_NAMING_FORMAT
 from picard.metadata import (
@@ -106,9 +105,9 @@ class ScriptParserTest(PicardTestCase):
 
     def setUp(self):
         super().setUp()
-        config.setting = {
+        self.set_config_values({
             'enabled_plugins': '',
-        }
+        })
 
         self.parser = ScriptParser()
 
diff --git a/test/test_scripttofilename.py b/test/test_scripttofilename.py
index 4789cbe30..f1f9ecb96 100644
--- a/test/test_scripttofilename.py
+++ b/test/test_scripttofilename.py
@@ -53,7 +53,7 @@ class ScriptToFilenameTest(PicardTestCase):
 
     def setUp(self):
         super().setUp()
-        config.setting = settings.copy()
+        self.set_config_values(settings)
 
     def test_plain_filename(self):
         metadata = Metadata()
diff --git a/test/test_settingsoverride.py b/test/test_settingsoverride.py
index 1ece9510b..ee19a1d39 100644
--- a/test/test_settingsoverride.py
+++ b/test/test_settingsoverride.py
@@ -28,8 +28,8 @@ from picard.util.settingsoverride import SettingsOverride
 class SettingsOverrideTest(PicardTestCase):
 
     def setUp(self):
-        self.config = {'key1': 'origval1', 'key2': 'origval2'}
-        config.setting = self.config.copy()
+        super().setUp()
+        self.set_config_values({'key1': 'origval1', 'key2': 'origval2'})
         self.new_settings = {'key1': 'newval2'}
 
     def test_read_orig_settings(self):
diff --git a/test/test_utils.py b/test/test_utils.py
index ffece9548..7456f3e1f 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -388,6 +388,7 @@ SimMatchTest = namedtuple('SimMatchTest', 'similarity name')
 class SortBySimilarity(PicardTestCase):
 
     def setUp(self):
+        super().setUp()
         self.test_values = [
             SimMatchTest(similarity=0.74, name='d'),
             SimMatchTest(similarity=0.61, name='a'),
@@ -435,6 +436,7 @@ class GetQtEnum(PicardTestCase):
 class LimitedJoin(PicardTestCase):
 
     def setUp(self):
+        super().setUp()
         self.list = [str(x) for x in range(0, 10)]
 
     def test_1(self):
diff --git a/test/test_webservice.py b/test/test_webservice.py
index 69ef13bbe..5c1c50546 100644
--- a/test/test_webservice.py
+++ b/test/test_webservice.py
@@ -55,17 +55,13 @@ class WebServiceTest(PicardTestCase):
 
     def setUp(self):
         super().setUp()
-        config.setting = {
+        self.set_config_values({
             'use_proxy': False,
             'server_host': '',
             'network_transfer_timeout_seconds': 30,
-        }
+        })
         self.ws = WebService()
 
-    def tearDown(self):
-        del self.ws
-        config.setting = {}
-
     @patch.object(WebService, 'add_task')
     def test_webservice_method_calls(self, mock_add_task):
         host = "abc.xyz"
@@ -97,20 +93,16 @@ class WebServiceTaskTest(PicardTestCase):
 
     def setUp(self):
         super().setUp()
-        config.setting = {
+        self.set_config_values({
             'use_proxy': False,
             'network_transfer_timeout_seconds': 30,
-        }
+        })
         self.ws = WebService()
 
         # Patching the QTimers since they can only be started in a QThread
         self.ws._timer_run_next_task = MagicMock()
         self.ws._timer_count_pending_requests = MagicMock()
 
-    def tearDown(self):
-        del self.ws
-        config.setting = {}
-
     def test_add_task(self):
 
         mock_timer1 = self.ws._timer_run_next_task
@@ -215,10 +207,7 @@ class WebServiceProxyTest(PicardTestCase):
 
     def setUp(self):
         super().setUp()
-        config.setting = PROXY_SETTINGS.copy()
-
-    def tearDown(self):
-        config.setting = {}
+        self.set_config_values(PROXY_SETTINGS)
 
     def test_proxy_setup(self):
         proxy_types = [