diff --git a/test/run_test.py b/test/run_test.py
index f91f0cc323cf..6f8126c5fef3 100755
--- a/test/run_test.py
+++ b/test/run_test.py
@@ -531,6 +531,7 @@ XPU_TEST = [
 
 # The tests inside these files should never be run in parallel with each other
 RUN_PARALLEL_BLOCKLIST = [
+    "test_extension_utils",
     "test_cpp_extensions_jit",
     "test_cpp_extensions_open_device_registration",
     "test_cpp_extensions_stream_and_event",
diff --git a/test/test_extension_utils.py b/test/test_extension_utils.py
new file mode 100644
index 000000000000..d624f93a1d3f
--- /dev/null
+++ b/test/test_extension_utils.py
@@ -0,0 +1,88 @@
+# Owner(s): ["module: PrivateUse1"]
+import sys
+
+import torch
+from torch.testing._internal.common_utils import run_tests, TestCase
+
+
+class DummyPrivateUse1Module:
+    @staticmethod
+    def is_available():
+        return True
+
+    @staticmethod
+    def is_autocast_enabled():
+        return True
+
+    @staticmethod
+    def get_autocast_dtype():
+        return torch.float16
+
+    @staticmethod
+    def set_autocast_enabled(enable):
+        pass
+
+    @staticmethod
+    def set_autocast_dtype(dtype):
+        pass
+
+    @staticmethod
+    def get_amp_supported_dtype():
+        return [torch.float16]
+
+
+class TestExtensionUtils(TestCase):
+    def tearDown(self):
+        # Clean up
+        backend_name = torch._C._get_privateuse1_backend_name()
+        if hasattr(torch, backend_name):
+            delattr(torch, backend_name)
+        if f"torch.{backend_name}" in sys.modules:
+            del sys.modules[f"torch.{backend_name}"]
+
+    def test_external_module_register(self):
+        # Built-in module
+        with self.assertRaisesRegex(RuntimeError, "The runtime module of"):
+            torch._register_device_module("cuda", torch.cuda)
+
+        # Wrong device type
+        with self.assertRaisesRegex(RuntimeError, "Expected one of cpu"):
+            torch._register_device_module("dummmy", DummyPrivateUse1Module)
+
+        with self.assertRaises(AttributeError):
+            torch.privateuseone.is_available()  # type: ignore[attr-defined]
+
+        torch._register_device_module("privateuseone", DummyPrivateUse1Module)
+
+        torch.privateuseone.is_available()  # type: ignore[attr-defined]
+
+        # No supporting for override
+        with self.assertRaisesRegex(RuntimeError, "The runtime module of"):
+            torch._register_device_module("privateuseone", DummyPrivateUse1Module)
+
+    def test_external_module_register_with_renamed_backend(self):
+        torch.utils.rename_privateuse1_backend("foo")
+        with self.assertRaisesRegex(RuntimeError, "has already been set"):
+            torch.utils.rename_privateuse1_backend("dummmy")
+
+        custom_backend_name = torch._C._get_privateuse1_backend_name()
+        self.assertEqual(custom_backend_name, "foo")
+
+        with self.assertRaises(AttributeError):
+            torch.foo.is_available()  # type: ignore[attr-defined]
+
+        with self.assertRaisesRegex(AssertionError, "Tried to use AMP with the"):
+            with torch.autocast(device_type=custom_backend_name):
+                pass
+        torch._register_device_module("foo", DummyPrivateUse1Module)
+
+        torch.foo.is_available()  # type: ignore[attr-defined]
+        with torch.autocast(device_type=custom_backend_name):
+            pass
+
+        self.assertEqual(torch._utils._get_device_index("foo:1"), 1)
+        self.assertEqual(torch._utils._get_device_index(torch.device("foo:2")), 2)
+
+
+if __name__ == "__main__":
+    run_tests()
diff --git a/test/test_utils.py b/test/test_utils.py
index 6ddc600be21f..0fdd59edce58 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -1002,85 +1002,6 @@ class TestStandaloneCPPJIT(TestCase):
             shutil.rmtree(build_dir)
 
 
-class DummyPrivateUse1Module:
-    @staticmethod
-    def is_available():
-        return True
-
-    @staticmethod
-    def is_autocast_enabled():
-        return True
-
-    @staticmethod
-    def get_autocast_dtype():
-        return torch.float16
-
-    @staticmethod
-    def set_autocast_enabled(enable):
-        pass
-
-    @staticmethod
-    def set_autocast_dtype(dtype):
-        pass
-
-    @staticmethod
-    def get_amp_supported_dtype():
-        return [torch.float16]
-
-
-class TestExtensionUtils(TestCase):
-    def tearDown(self):
-        # Clean up
-        backend_name = torch._C._get_privateuse1_backend_name()
-        if hasattr(torch, backend_name):
-            delattr(torch, backend_name)
-        if f"torch.{backend_name}" in sys.modules:
-            del sys.modules[f"torch.{backend_name}"]
-
-    def test_external_module_register(self):
-        # Built-in module
-        with self.assertRaisesRegex(RuntimeError, "The runtime module of"):
-            torch._register_device_module("cuda", torch.cuda)
-
-        # Wrong device type
-        with self.assertRaisesRegex(RuntimeError, "Expected one of cpu"):
-            torch._register_device_module("dummmy", DummyPrivateUse1Module)
-
-        with self.assertRaises(AttributeError):
-            torch.privateuseone.is_available()  # type: ignore[attr-defined]
-
-        torch._register_device_module("privateuseone", DummyPrivateUse1Module)
-
-        torch.privateuseone.is_available()  # type: ignore[attr-defined]
-
-        # No supporting for override
-        with self.assertRaisesRegex(RuntimeError, "The runtime module of"):
-            torch._register_device_module("privateuseone", DummyPrivateUse1Module)
-
-    def test_external_module_register_with_renamed_backend(self):
-        torch.utils.rename_privateuse1_backend("foo")
-        with self.assertRaisesRegex(RuntimeError, "has already been set"):
-            torch.utils.rename_privateuse1_backend("dummmy")
-
-        custom_backend_name = torch._C._get_privateuse1_backend_name()
-        self.assertEqual(custom_backend_name, "foo")
-
-        with self.assertRaises(AttributeError):
-            torch.foo.is_available()  # type: ignore[attr-defined]
-
-        with self.assertRaisesRegex(AssertionError, "Tried to use AMP with the"):
-            with torch.autocast(device_type=custom_backend_name):
-                pass
-        torch._register_device_module("foo", DummyPrivateUse1Module)
-
-        torch.foo.is_available()  # type: ignore[attr-defined]
-        with torch.autocast(device_type=custom_backend_name):
-            pass
-
-        self.assertEqual(torch._utils._get_device_index("foo:1"), 1)
-        self.assertEqual(torch._utils._get_device_index(torch.device("foo:2")), 2)
-
-
 class TestRenderUtils(TestCase):
     def test_basic(self):
         self.assertExpectedInline(