diff --git a/llmfoundry/optim/no_op.py b/llmfoundry/optim/no_op.py
index f435917b36..416363c261 100644
--- a/llmfoundry/optim/no_op.py
+++ b/llmfoundry/optim/no_op.py
@@ -1,13 +1,25 @@
+# Copyright 2024 MosaicML LLM Foundry authors
+# SPDX-License-Identifier: Apache-2.0
+
+from typing import Any, Callable, Iterable, Optional
+
 import torch
-from typing import Iterable, Any, Optional, Callable
+
 
 class NoOp(torch.optim.Optimizer):
+    """Optimizer that performs no optimization steps."""
+
     def __init__(
         self,
         params: Iterable[torch.Tensor],
     ):
+        """Initialize NoOp optimizer.
+
+        Args:
+            params (Iterable[torch.Tensor]): Model parameters for the optimizer.
+        """
         # LR schedulers expect param groups to have LR. Unused.
-        defaults = {"lr": 0.0}
+        defaults = {'lr': 0.0}
         super().__init__(params, defaults)
 
     def __setstate__(self, state: dict[str, dict[Any, Any]]) -> None:
@@ -29,4 +41,4 @@ def step(self, closure: Optional[Callable] = None):
             with torch.enable_grad():
                 loss = closure()
 
-        return loss
\ No newline at end of file
+        return loss
diff --git a/tests/optim/test_no_op.py b/tests/optim/test_no_op.py
index eb1c2fb704..27766d6eaf 100644
--- a/tests/optim/test_no_op.py
+++ b/tests/optim/test_no_op.py
@@ -1,13 +1,15 @@
 # Copyright 2022 MosaicML LLM Foundry authors
 # SPDX-License-Identifier: Apache-2.0
 
-import torch
+import copy
 from typing import Callable
+
+import torch
+from composer.trainer import Trainer
 from torch.utils.data import DataLoader
+
 from llmfoundry.models.mpt.modeling_mpt import ComposerMPTCausalLM
-from composer.trainer import Trainer
 from llmfoundry.utils.builders import build_optimizer
-import copy
 
 
 def test_no_op_does_nothing(
@@ -20,7 +22,7 @@ def test_no_op_does_nothing(
         loss_fn='torch_crossentropy',
         attn_config={
             'attn_impl': 'torch',
-        }
+        },
     )
 
     # Build NoOp optimizer
@@ -38,6 +40,9 @@ def test_no_op_does_nothing(
     trainer.fit()
 
     # Check that the model has not changed
-    for ((orig_name, orig_param), (new_name, new_param)) in zip(orig_model.named_parameters(), model.named_parameters()):
+    for (
+        (orig_name, orig_param),
+        (new_name, new_param),
+    ) in zip(orig_model.named_parameters(), model.named_parameters()):
         print(f'Checking {orig_name} and {new_name}')
         assert torch.equal(orig_param, new_param)