diff --git a/pyproject.toml b/pyproject.toml
index e88fb646..f057ed15 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -69,7 +69,7 @@ db = [
 memcached = ["pylibmc"]
 supervisor = ["supervisor"]
 docs = ["Sphinx", "sphinx-paramlinks", "sphinxcontrib-programoutput", "furo"]
-tests = ["coverage", "mock", "pytest", "pytest-cov"]
+tests = ["pytest-cov", "tox"]
 
 
 [project.scripts]
diff --git a/rattail/db/changes.py b/rattail/db/changes.py
index 3940c573..6f64e0b4 100644
--- a/rattail/db/changes.py
+++ b/rattail/db/changes.py
@@ -30,17 +30,13 @@ from packaging.version import parse as parse_version
 import sqlalchemy as sa
 from sqlalchemy.orm import object_mapper, RelationshipProperty
 from sqlalchemy.orm.session import Session
-
-try:
-    from sqlalchemy.event import listen
-except ImportError:
-    listen = None # old SQLAlchemy; will have to work around that, below
+from sqlalchemy.event import listen
 
 from rattail.db.model import Setting, Change, DataSyncChange
 
 try:
     from rattail.db.continuum import versioning_manager
-except ImportError:             # assume no continuum
+except ImportError: # pragma: no cover
     versioning_manager = None
 
 
@@ -49,10 +45,14 @@ log = logging.getLogger(__name__)
 
 def record_changes(session, recorder=None, config=None):
     """
-    Record all relevant data changes which occur within a session.
+    Turn on the "record changes" feature.
 
-    :param session: A :class:`sqlalchemy:sqlalchemy.orm.session.Session` class,
-       or instance thereof.
+    With this enabled, all relevant data changes which occur in the
+    sesion will be recorded.
+
+    :param session: A
+       :class:`sqlalchemy:sqlalchemy.orm.session.Session` class, or
+       instance thereof.
     """
     if isinstance(recorder, ChangeRecorder):
         pass
@@ -61,23 +61,15 @@ def record_changes(session, recorder=None, config=None):
     elif recorder is None:
         if config:
             app = config.get_app()
-            spec = config.get('rattail.db', 'changes.recorder', usedb=False)
+            spec = config.get('rattail.db.changes.recorder', usedb=False)
             if spec:
                 recorder = app.load_object(spec)(config)
         if not recorder:
             recorder = ChangeRecorder(config)
     else:
-        raise ValueError("Invalid 'recorder' parameter: {}".format(repr(recorder)))
-
-    if listen:
-        listen(session, 'before_flush', recorder)
-    else:
-        extension = ChangeRecorderExtension(recorder)
-        if isinstance(session, Session):
-            session.extensions.append(extension)
-        else:
-            session.configure(extension=extension)
+        raise ValueError(f"recorder not valid: {recorder}")
 
+    listen(session, 'before_flush', recorder)
     session.rattail_record_changes = True
     session.rattail_change_recorder = recorder
 
diff --git a/rattail/testing.py b/rattail/testing.py
index 568f71a7..8e7b7097 100644
--- a/rattail/testing.py
+++ b/rattail/testing.py
@@ -1,10 +1,10 @@
 # -*- coding: utf-8; -*-
 
-from wuttjamaican.testing import FileConfigTestCase
+from wuttjamaican.testing import FileTestCase
 from rattail.config import RattailConfig
 
 
-class DataTestCase(FileConfigTestCase):
+class DataTestCase(FileTestCase):
     """
     Base class for test suites requiring a full (typical) database.
     """
@@ -14,7 +14,9 @@ class DataTestCase(FileConfigTestCase):
 
     def setup_db(self):
         self.setup_files()
-        self.config = self.make_config()
+        self.config = self.make_config(defaults={
+            'rattail.db.default.url': 'sqlite://',
+        })
         self.app = self.config.get_app()
 
         # init db
@@ -28,7 +30,5 @@ class DataTestCase(FileConfigTestCase):
     def teardown_db(self):
         self.teardown_files()
 
-    def make_config(self):
-        return RattailConfig(defaults={
-            'rattail.db.default.url': 'sqlite://',
-        })
+    def make_config(self, **kwargs):
+        return RattailConfig(**kwargs)
diff --git a/tests/db/test_changes.py b/tests/db/test_changes.py
index e365e97d..3c589b4a 100644
--- a/tests/db/test_changes.py
+++ b/tests/db/test_changes.py
@@ -1,86 +1,58 @@
 # -*- coding: utf-8; -*-
 
 from unittest import TestCase
-from unittest.mock import patch, DEFAULT, Mock, MagicMock, call
+from unittest.mock import patch, DEFAULT, Mock, MagicMock
 
 from rattail.config import RattailConfig
+from rattail.testing import DataTestCase
+
 
 try:
     from sqlalchemy import orm
     from rattail import db
+    from rattail.db import changes as mod
     from rattail.db import changes, model
-    from .. import DataTestCase
 except ImportError:
     pass
 else:
 
-    class TestRecordChangesFunc(TestCase):
 
-        def setUp(self):
-            self.config = RattailConfig()
-            self.app = self.config.get_app()
+    class MockRecorder:
+        def __init__(self, config):
+            pass
 
-        def test_session_class(self):
-            Session = orm.sessionmaker()
-            if hasattr(Session, 'kw'):
-                self.assertRaises(KeyError, Session.kw.__getitem__, 'rattail_record_changes')
-            self.assertRaises(AttributeError, getattr, Session, 'rattail_record_changes')
-            changes.record_changes(Session)
-            self.assertTrue(Session.rattail_record_changes)
 
-        def test_session_instance(self):
-            session = db.Session()
-            self.assertFalse(session.rattail_record_changes)
-            changes.record_changes(session)
-            self.assertTrue(session.rattail_record_changes)
-            session.close()
+    class TestRecordChanges(DataTestCase):
 
-        def test_recorder(self):
+        def test_recorder_instance(self):
+            recorder = mod.ChangeRecorder(self.config)
+            self.assertFalse(self.session.rattail_record_changes)
+            mod.record_changes(self.session, recorder=recorder)
+            self.assertTrue(self.session.rattail_record_changes)
 
-            # no recorder
-            session = db.Session()
-            self.assertRaises(AttributeError, getattr, session, 'rattail_change_recorder')
-            session.close()
+        def test_recorder_factory(self):
+            self.assertFalse(self.session.rattail_record_changes)
+            mod.record_changes(self.session, recorder=mod.ChangeRecorder, config=self.config)
+            self.assertTrue(self.session.rattail_record_changes)
 
-            # default recorder
-            session = db.Session()
-            changes.record_changes(session)
-            self.assertIs(type(session.rattail_change_recorder), changes.ChangeRecorder)
-            session.close()
+        def test_configured_recorder(self):
+            self.config.setdefault('rattail.db.changes.recorder', 'tests.db.test_changes:MockRecorder')
+            self.assertFalse(self.session.rattail_record_changes)
+            mod.record_changes(self.session, config=self.config)
+            self.assertTrue(self.session.rattail_record_changes)
 
-            # specify recorder instance
-            recorder = changes.ChangeRecorder(self.config)
-            session = db.Session()
-            changes.record_changes(session, recorder=recorder)
-            self.assertIs(session.rattail_change_recorder, recorder)
-            session.close()
+        def test_default_recorder(self):
+            self.assertFalse(self.session.rattail_record_changes)
+            mod.record_changes(self.session, config=self.config)
+            self.assertTrue(self.session.rattail_record_changes)
 
-            # specify recorder factory
-            session = db.Session()
-            changes.record_changes(session, recorder=changes.ChangeRecorder, config=self.config)
-            self.assertIs(type(session.rattail_change_recorder), changes.ChangeRecorder)
-            session.close()
-
-            # specify recorder spec via config
-            config = RattailConfig()
-            config.setdefault('rattail.db', 'changes.recorder', 'rattail.db.changes:ChangeRecorder')
-            session = db.Session()
-            changes.record_changes(session, config=config)
-            self.assertIs(type(session.rattail_change_recorder), changes.ChangeRecorder)
-            session.close()
-
-            # invalid recorder
-            session = db.Session()
-            self.assertRaises(ValueError, changes.record_changes, session, recorder='bogus')
-            session.close()
+        def test_invalid_recorder(self):
+            self.assertFalse(self.session.rattail_record_changes)
+            self.assertRaises(ValueError, mod.record_changes, self.session, recorder=42)
 
 
     class TestChangeRecorder(DataTestCase):
 
-        def extra_setup(self):
-            self.config = RattailConfig()
-            self.app = self.config.get_app()
-
         def test_ignore_object(self):
             recorder = changes.ChangeRecorder(self.config)
             self.assertTrue(recorder.ignore_object(model.Setting()))
@@ -311,8 +283,7 @@ else:
     class TestFunctionalChanges(DataTestCase):
 
         def setUp(self):
-            super().setUp()
-            self.config = RattailConfig()
+            self.setup_db()
             changes.record_changes(self.session, config=self.config)
 
         def test_add(self):
diff --git a/tests/test_app.py b/tests/test_app.py
index 102b0b99..85369594 100644
--- a/tests/test_app.py
+++ b/tests/test_app.py
@@ -16,11 +16,20 @@ from rattail.core import Object
 from rattail.db import Session
 from rattail.autocomplete import Autocompleter
 from rattail.batch import BatchHandler
-from rattail.bouncer import BounceHandler
 from rattail.importing import ImportHandler
 from rattail.gpc import GPC
 
 
+try:
+    from rattail.bouncer import BounceHandler
+except ImportError:
+    pass
+else:
+
+    class FooBarBounceHandler(BounceHandler):
+        pass
+
+
 class TestAppHandler(TestCase):
 
     def setUp(self):
@@ -251,6 +260,11 @@ class TestAppHandler(TestCase):
 
     def test_get_bounce_handler(self):
 
+        try:
+            from rattail.bouncer import BounceHandler
+        except ImportError:
+            pytest.skip("test not relevant without flufl.bounce")
+
         # unknown type raises error by default
         self.assertRaises(ValueError, self.app.get_bounce_handler, 'foobar')
 
@@ -827,10 +841,6 @@ class FooBarBatchHandler(BatchHandler):
     pass
 
 
-class FooBarBounceHandler(BounceHandler):
-    pass
-
-
 class FromFooToBar(ImportHandler):
     host_key = 'rattail'
     local_key = 'rattail'
diff --git a/tox.ini b/tox.ini
index 65eede6d..d0490f76 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,13 +1,13 @@
 
 [tox]
-envlist = py38, py39, py310, py311, nodb
+envlist = py38, py39, py310, py311, nox
 
 [testenv]
 extras = bouncer,db,tests
 commands = pytest {posargs}
 
-[testenv:nodb]
-extras = bouncer,tests
+[testenv:nox]
+extras = tests
 
 [testenv:coverage]
 basepython = python3