diff --git a/docs/examples/plot_3d_to_2d.py b/docs/examples/plot_3d_to_2d.py
index 89bf9a4b..bd897e20 100644
--- a/docs/examples/plot_3d_to_2d.py
+++ b/docs/examples/plot_3d_to_2d.py
@@ -36,7 +36,7 @@ def plot_batch(sampler):
     loader = tio.SubjectsLoader(queue, batch_size=16)
     batch = tio.utils.get_first_item(loader)
 
-    fig, axes = plt.subplots(4, 4, figsize=(12, 10))
+    _, axes = plt.subplots(4, 4, figsize=(12, 10))
     for ax, im in zip(axes.flatten(), batch['t1']['data']):
         ax.imshow(im.squeeze(), cmap='gray')
     plt.suptitle(sampler.__class__.__name__)
diff --git a/pyproject.toml b/pyproject.toml
index 9bb3074c..0715c80f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -133,6 +133,7 @@ filterwarnings = [
 quote-style = 'single'
 
 [tool.ruff.lint]
+preview = true
 select = [
     "B",
     "E",