diff --git a/mjx/mujoco/mjx/warp/collision_driver_test.py b/mjx/mujoco/mjx/warp/collision_driver_test.py
index 93e72db3..36109eef 100644
--- a/mjx/mujoco/mjx/warp/collision_driver_test.py
+++ b/mjx/mujoco/mjx/warp/collision_driver_test.py
@@ -39,18 +39,23 @@ _FORCE_TEST = os.environ.get('MJX_WARP_FORCE_TEST', '0') == '1'
 
 class CollisionTest(absltest.TestCase):
 
+  @classmethod
+  def setUpClass(cls):
+    super().setUpClass()
+    if mjxw.WARP_INSTALLED:
+      cls.tempdir = tempfile.TemporaryDirectory()
+      wp.config.kernel_cache_dir = cls.tempdir.name
+
+  @classmethod
+  def tearDownClass(cls):
+    super().tearDownClass()
+    if hasattr(cls, 'tempdir'):
+      cls.tempdir.cleanup()
+
   def setUp(self):
     super().setUp()
-    if mjxw.WARP_INSTALLED:
-      self.tempdir = tempfile.TemporaryDirectory()
-      wp.config.kernel_cache_dir = self.tempdir.name
     np.random.seed(0)
 
-  def tearDown(self):
-    super().tearDown()
-    if hasattr(self, 'tempdir'):
-      self.tempdir.cleanup()
-
   _SPHERE_SPHERE = """
     <mujoco>
       <worldbody>
diff --git a/mjx/mujoco/mjx/warp/forward_test.py b/mjx/mujoco/mjx/warp/forward_test.py
index fe65576b..aa0700a6 100644
--- a/mjx/mujoco/mjx/warp/forward_test.py
+++ b/mjx/mujoco/mjx/warp/forward_test.py
@@ -41,18 +41,23 @@ _FORCE_TEST = os.environ.get('MJX_WARP_FORCE_TEST', '0') == '1'
 
 class ForwardTest(parameterized.TestCase):
 
+  @classmethod
+  def setUpClass(cls):
+    super().setUpClass()
+    if mjxw.WARP_INSTALLED:
+      cls.tempdir = tempfile.TemporaryDirectory()
+      wp.config.kernel_cache_dir = cls.tempdir.name
+
+  @classmethod
+  def tearDownClass(cls):
+    super().tearDownClass()
+    if hasattr(cls, 'tempdir'):
+      cls.tempdir.cleanup()
+
   def setUp(self):
     super().setUp()
-    if mjxw.WARP_INSTALLED:
-      self.tempdir = tempfile.TemporaryDirectory()
-      wp.config.kernel_cache_dir = self.tempdir.name
     np.random.seed(0)
 
-  def tearDown(self):
-    super().tearDown()
-    if hasattr(self, 'tempdir'):
-      self.tempdir.cleanup()
-
   @parameterized.parameters(
       'pendula.xml',
       'humanoid/humanoid.xml',
@@ -198,18 +203,23 @@ class ForwardTest(parameterized.TestCase):
 
 class StepTest(parameterized.TestCase):
 
+  @classmethod
+  def setUpClass(cls):
+    super().setUpClass()
+    if mjxw.WARP_INSTALLED:
+      cls.tempdir = tempfile.TemporaryDirectory()
+      wp.config.kernel_cache_dir = cls.tempdir.name
+
+  @classmethod
+  def tearDownClass(cls):
+    super().tearDownClass()
+    if hasattr(cls, 'tempdir'):
+      cls.tempdir.cleanup()
+
   def setUp(self):
     super().setUp()
-    if mjxw.WARP_INSTALLED:
-      self.tempdir = tempfile.TemporaryDirectory()
-      wp.config.kernel_cache_dir = self.tempdir.name
     np.random.seed(0)
 
-  def tearDown(self):
-    super().tearDown()
-    if hasattr(self, 'tempdir'):
-      self.tempdir.cleanup()
-
   @parameterized.product(
       xml=(
           'humanoid/humanoid.xml',
diff --git a/mjx/mujoco/mjx/warp/smooth_test.py b/mjx/mujoco/mjx/warp/smooth_test.py
index b2f867a5..92c02875 100644
--- a/mjx/mujoco/mjx/warp/smooth_test.py
+++ b/mjx/mujoco/mjx/warp/smooth_test.py
@@ -41,18 +41,23 @@ _FORCE_TEST = os.environ.get('MJX_WARP_FORCE_TEST', '0') == '1'
 
 class SmoothTest(parameterized.TestCase):
 
+  @classmethod
+  def setUpClass(cls):
+    super().setUpClass()
+    if mjxw.WARP_INSTALLED:
+      cls.tempdir = tempfile.TemporaryDirectory()
+      wp.config.kernel_cache_dir = cls.tempdir.name
+
+  @classmethod
+  def tearDownClass(cls):
+    super().tearDownClass()
+    if hasattr(cls, 'tempdir'):
+      cls.tempdir.cleanup()
+
   def setUp(self):
     super().setUp()
-    if mjxw.WARP_INSTALLED:
-      self.tempdir = tempfile.TemporaryDirectory()
-      wp.config.kernel_cache_dir = self.tempdir.name
     np.random.seed(0)
 
-  def tearDown(self):
-    super().tearDown()
-    if hasattr(self, 'tempdir'):
-      self.tempdir.cleanup()
-
   def test_kinematics(self):
     """Tests kinematics with unbatched data."""
     if not _FORCE_TEST: