diff --git a/monai/bundle/config_item.py b/monai/bundle/config_item.py
index 98babfb225..34a390be5f 100644
--- a/monai/bundle/config_item.py
+++ b/monai/bundle/config_item.py
@@ -106,7 +106,7 @@ def get_component_module_name(self, name: str) -> Optional[Union[List[str], str]
             # init component and module mapping table
             self._components_table = self._find_classes_or_functions(self._find_module_names())
 
-        mods: Optional[Union[List[str], str]] = self._components_table.get(name, None)
+        mods: Optional[Union[List[str], str]] = self._components_table.get(name)
         if isinstance(mods, list) and len(mods) == 1:
             mods = mods[0]
         return mods
diff --git a/monai/data/dataloader.py b/monai/data/dataloader.py
index e8ff23a5a3..f43211f184 100644
--- a/monai/data/dataloader.py
+++ b/monai/data/dataloader.py
@@ -76,7 +76,7 @@ def __init__(self, dataset: Dataset, num_workers: int = 0, **kwargs) -> None:
             # when num_workers > 0, random states are determined by worker_init_fn
             # this is to make the behavior consistent when num_workers == 0
             # torch.int64 doesn't work well on some versions of windows
-            _g = torch.random.default_generator if kwargs.get("generator", None) is None else kwargs["generator"]
+            _g = torch.random.default_generator if kwargs.get("generator") is None else kwargs["generator"]
             init_seed = _g.initial_seed()
             _seed = torch.empty((), dtype=torch.int64).random_(generator=_g).item()
             set_rnd(dataset, int(_seed))
diff --git a/monai/utils/misc.py b/monai/utils/misc.py
index ae62f26635..d4bea4d27c 100644
--- a/monai/utils/misc.py
+++ b/monai/utils/misc.py
@@ -397,7 +397,7 @@ class MONAIEnvVars:
 
     @staticmethod
     def data_dir() -> Optional[str]:
-        return os.environ.get("MONAI_DATA_DIRECTORY", None)
+        return os.environ.get("MONAI_DATA_DIRECTORY")
 
     @staticmethod
     def debug() -> bool:
@@ -406,7 +406,7 @@ def debug() -> bool:
 
     @staticmethod
     def doc_images() -> Optional[str]:
-        return os.environ.get("MONAI_DOC_IMAGES", None)
+        return os.environ.get("MONAI_DOC_IMAGES")
 
 
 class ImageMetaKey:
diff --git a/tests/test_gmm.py b/tests/test_gmm.py
index f085dd916c..66bd6079e6 100644
--- a/tests/test_gmm.py
+++ b/tests/test_gmm.py
@@ -259,7 +259,7 @@
 @skip_if_no_cuda
 class GMMTestCase(unittest.TestCase):
     def setUp(self):
-        self._var = os.environ.get("TORCH_EXTENSIONS_DIR", None)
+        self._var = os.environ.get("TORCH_EXTENSIONS_DIR")
         self.tempdir = tempfile.mkdtemp()
         os.environ["TORCH_EXTENSIONS_DIR"] = self.tempdir
 
diff --git a/tests/test_monai_env_vars.py b/tests/test_monai_env_vars.py
index 68d2755af7..663dcdd98d 100644
--- a/tests/test_monai_env_vars.py
+++ b/tests/test_monai_env_vars.py
@@ -19,7 +19,7 @@ class TestMONAIEnvVars(unittest.TestCase):
     @classmethod
     def setUpClass(cls):
         super(__class__, cls).setUpClass()
-        cls.orig_value = os.environ.get("MONAI_DEBUG", None)
+        cls.orig_value = os.environ.get("MONAI_DEBUG")
 
     @classmethod
     def tearDownClass(cls):
diff --git a/tests/test_transform.py b/tests/test_transform.py
index 9cf18b8dbd..a6c5001147 100644
--- a/tests/test_transform.py
+++ b/tests/test_transform.py
@@ -29,7 +29,7 @@ class TestTransform(unittest.TestCase):
     @classmethod
     def setUpClass(cls):
         super(__class__, cls).setUpClass()
-        cls.orig_value = os.environ.get("MONAI_DEBUG", None)
+        cls.orig_value = os.environ.get("MONAI_DEBUG")
 
     @classmethod
     def tearDownClass(cls):