diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 2582e53..351ca54 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -20,7 +20,9 @@ jobs:
         with:
           python-version: ${{ matrix.python }}
       - name: Install dependencies
-        run: python -m pip install tox
+        run: python -m pip install tox ruff
+      - name: Run ruff
+        run: ruff check .
       - name: Run unit tests (via tox)
         # Run tox using the version of Python in `PATH`
         run: tox -e py
diff --git a/fixtures/__init__.py b/fixtures/__init__.py
index ad2e33f..f78e113 100644
--- a/fixtures/__init__.py
+++ b/fixtures/__init__.py
@@ -80,7 +80,7 @@
 ]
 
 
-from fixtures.fixture import (
+from fixtures.fixture import (  # noqa: E402
     CompoundFixture,
     Fixture,
     FunctionFixture,
@@ -88,7 +88,7 @@
     MultipleExceptions,
     SetupError,
 )
-from fixtures._fixtures import (
+from fixtures._fixtures import (  # noqa: E402
     ByteStream,
     DetailStream,
     EnvironmentVariable,
@@ -114,11 +114,11 @@
     WarningsCapture,
     WarningsFilter,
 )
-from fixtures.testcase import TestWithFixtures
+from fixtures.testcase import TestWithFixtures  # noqa: E402
 
 
 def test_suite():
-    import fixtures.tests
+    import fixtures.tests  # noqa: F401
 
     return fixtures.tests.test_suite()
 
diff --git a/fixtures/fixture.py b/fixtures/fixture.py
index fe028b5..f563e4a 100644
--- a/fixtures/fixture.py
+++ b/fixtures/fixture.py
@@ -194,7 +194,7 @@ def setUp(self):
         self._clear_cleanups()
         try:
             self._setUp()
-        except:
+        except BaseException:
             err = sys.exc_info()
             details = {}
             if gather_details is not None:
@@ -380,12 +380,14 @@ def setUp(self):
         if setup is None:
             setup = getattr(obj, 'setUp', None)
             if setup is None:
-                setup = lambda: None
+                def setup():
+                    return None
         self._setup = setup
         if cleanup is None:
             cleanup = getattr(obj, 'tearDown', None)
             if cleanup is None:
-                cleanup = lambda: None
+                def cleanup():
+                    return None
         self._cleanup = cleanup
         if reset is None:
             reset = getattr(obj, 'reset', None)
diff --git a/fixtures/tests/_fixtures/test_logger.py b/fixtures/tests/_fixtures/test_logger.py
index 95703f0..8f23cff 100644
--- a/fixtures/tests/_fixtures/test_logger.py
+++ b/fixtures/tests/_fixtures/test_logger.py
@@ -134,7 +134,7 @@ def test_logging_output_included_in_details(self):
             self.assertEqual("some message\n", content.as_text())
         except AssertionError:
             raise
-        except:
+        except BaseException:
             pass
 
     def test_exceptionraised(self):
diff --git a/fixtures/tests/_fixtures/test_monkeypatch.py b/fixtures/tests/_fixtures/test_monkeypatch.py
index 34a3ec2..8113261 100644
--- a/fixtures/tests/_fixtures/test_monkeypatch.py
+++ b/fixtures/tests/_fixtures/test_monkeypatch.py
@@ -113,7 +113,7 @@ def test_patch_missing_attribute(self):
         self.assertFalse('new_attr' in globals())
         fixture.setUp()
         try:
-            self.assertEqual(True, new_attr)
+            self.assertEqual(True, new_attr)  # noqa: F821
         finally:
             fixture.cleanUp()
             self.assertFalse('new_attr' in globals())