diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..53fbc82
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,33 @@
+name: lint
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+jobs:
+  pre-commit:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+          cache: "pip" # caching pip dependencies
+
+      - run: pip install -e '.[dev]'
+
+      - name: Ruff format
+        uses: chartboost/ruff-action@v1
+        with:
+          args: format --check
+
+      - name: Ruff lint
+        uses: chartboost/ruff-action@v1
+
+      - name: Mypy
+        run: |
+          mypy src/
diff --git a/src/torch_featurelayer/feature_layer.py b/src/torch_featurelayer/feature_layer.py
index d07f45c..0030cfb 100644
--- a/src/torch_featurelayer/feature_layer.py
+++ b/src/torch_featurelayer/feature_layer.py
@@ -52,6 +52,7 @@ def hook(module: torch.nn.Module, input: tuple[torch.Tensor, ...], output: torch
         output: torch.Tensor = self._model(*args, **kwargs)
 
         # Remove hook
-        h.remove()
+        if h is not None:
+            h.remove()
 
         return self.feature_layer_output, output
diff --git a/src/torch_featurelayer/feature_layers.py b/src/torch_featurelayer/feature_layers.py
index d35d002..59ac27f 100644
--- a/src/torch_featurelayer/feature_layers.py
+++ b/src/torch_featurelayer/feature_layers.py
@@ -1,4 +1,3 @@
-from collections import OrderedDict
 from typing import Any
 
 import torch
@@ -22,9 +21,9 @@ class FeatureLayers:
     def __init__(self, model: torch.nn.Module, feature_layer_paths: list[str]):
         self._model: torch.nn.Module = model
         self.feature_layer_paths: list[str] = feature_layer_paths
-        self.feature_layer_outputs: dict[str, torch.Tensor] = OrderedDict().fromkeys(feature_layer_paths, None)
+        self.feature_layer_outputs: dict[str, torch.Tensor | None] = dict().fromkeys(feature_layer_paths, None)
 
-    def __call__(self, *args: Any, **kwargs: Any) -> tuple[dict[str, torch.Tensor], torch.Tensor]:
+    def __call__(self, *args: Any, **kwargs: Any) -> tuple[dict[str, torch.Tensor | None], torch.Tensor]:
         """Perform a forward pass through the model and update the hooked feature layers.
 
         Args: