diff --git a/lib/iris/tests/unit/common/lenient/test__qualname.py b/lib/iris/tests/unit/common/lenient/test__qualname.py
index 49576814d4..69d2d229e1 100644
--- a/lib/iris/tests/unit/common/lenient/test__qualname.py
+++ b/lib/iris/tests/unit/common/lenient/test__qualname.py
@@ -4,25 +4,23 @@
 # See LICENSE in the root of the repository for full licensing details.
 """Unit tests for the :func:`iris.common.lenient._qualname`."""
 
-# Import iris.tests first so that some things can be initialised before
-# importing anything else.
-import iris.tests as tests  # isort:skip
-
 from inspect import getmodule
-from unittest.mock import sentinel
+
+import pytest
 
 from iris.common.lenient import _qualname
 
 
-class Test(tests.IrisTest):
-    def setUp(self):
+class Test:
+    @pytest.fixture(autouse=True)
+    def _setup(self):
         module_name = getmodule(self).__name__
         self.locals = f"{module_name}" + ".Test.{}.<locals>.{}"
 
-    def test_pass_thru_non_callable(self):
-        func = sentinel.func
+    def test_pass_thru_non_callable(self, mocker):
+        func = mocker.sentinel.func
         result = _qualname(func)
-        self.assertEqual(result, func)
+        assert result == func
 
     def test_callable_function_local(self):
         def myfunc():
@@ -30,13 +28,13 @@ def myfunc():
 
         qualname_func = self.locals.format("test_callable_function_local", "myfunc")
         result = _qualname(myfunc)
-        self.assertEqual(result, qualname_func)
+        assert result == qualname_func
 
     def test_callable_function(self):
         import iris
 
         result = _qualname(iris.load)
-        self.assertEqual(result, "iris.load")
+        assert result == "iris.load"
 
     def test_callable_method_local(self):
         class MyClass:
@@ -47,14 +45,10 @@ def mymethod(self):
             "test_callable_method_local", "MyClass.mymethod"
         )
         result = _qualname(MyClass.mymethod)
-        self.assertEqual(result, qualname_method)
+        assert result == qualname_method
 
     def test_callable_method(self):
         import iris
 
         result = _qualname(iris.cube.Cube.add_ancillary_variable)
-        self.assertEqual(result, "iris.cube.Cube.add_ancillary_variable")
-
-
-if __name__ == "__main__":
-    tests.main()
+        assert result == "iris.cube.Cube.add_ancillary_variable"