diff --git a/ogstools/meshplotlib/animation.py b/ogstools/meshplotlib/animation.py
index 0df18f1cc812e25a312bc0e0e9fcbda54af6d99a..295d97e42b756873e41842e65a034a6c94406e30 100644
--- a/ogstools/meshplotlib/animation.py
+++ b/ogstools/meshplotlib/animation.py
@@ -1,8 +1,7 @@
 import warnings
 from collections.abc import Sequence
 from functools import partial
-from typing import Optional as Opt
-from typing import Union
+from typing import Optional, Union
 
 import matplotlib as mpl
 import numpy as np
@@ -20,8 +19,8 @@ from .core import _plot_on_figure, plot
 def animate(
     mesh_series: MeshSeries,
     property: Property,
-    timesteps: Opt[Sequence] = None,
-    titles: Opt[list[str]] = None,
+    timesteps: Optional[Sequence] = None,
+    titles: Optional[list[str]] = None,
 ) -> FuncAnimation:
     """
     Create an animation for a property of a mesh series with given timesteps.
diff --git a/ogstools/meshplotlib/core.py b/ogstools/meshplotlib/core.py
index f8567270ff6f0a5a2b14ca42b4800521afd76bd6..682f24fdcafb867a6db86cb6472fcd7d54ee09ee 100644
--- a/ogstools/meshplotlib/core.py
+++ b/ogstools/meshplotlib/core.py
@@ -2,8 +2,7 @@
 
 import types
 from copy import deepcopy
-from typing import Literal, Union
-from typing import Optional as Opt
+from typing import Literal, Optional, Union
 
 import numpy as np
 import pyvista as pv
@@ -115,7 +114,7 @@ def add_colorbars(
     property: Property,
     levels: np.ndarray,
     pad: float = 0.05,
-    labelsize: Opt[float] = None,
+    labelsize: Optional[float] = None,
 ) -> None:
     """Add a colorbar to the matplotlib figure."""
     cmap, norm = get_cmap_norm(levels, property)
@@ -178,7 +177,7 @@ def subplot(
     mesh: pv.UnstructuredGrid,
     property: Union[Property, str],
     ax: plt.Axes,
-    levels: Opt[np.ndarray] = None,
+    levels: Optional[np.ndarray] = None,
 ) -> None:
     """
     Plot the property field of a mesh on a matplotlib.axis.
diff --git a/ogstools/physics/nuclearwasteheat/nuclearwaste.py b/ogstools/physics/nuclearwasteheat/nuclearwaste.py
index 3377556846152cb681efcc5303c82e8929718b6c..86f417d35ef41876fb6f258c3ba04f207dd9140c 100644
--- a/ogstools/physics/nuclearwasteheat/nuclearwaste.py
+++ b/ogstools/physics/nuclearwasteheat/nuclearwaste.py
@@ -1,6 +1,5 @@
 from dataclasses import dataclass
-from typing import Optional as Opt
-from typing import Union
+from typing import Optional, Union
 
 import numpy as np
 from pint.facets.plain import PlainQuantity
@@ -31,7 +30,7 @@ class NuclearWaste:
         self,
         t: Union[PlainQuantity, float, np.ndarray],
         baseline: bool = False,
-        ncl_id: Opt[int] = None,
+        ncl_id: Optional[int] = None,
         time_unit: str = "s",
         power_unit: str = "W",
     ) -> Union[float, np.ndarray]:
@@ -84,7 +83,7 @@ class Repository:
         self,
         t: Union[PlainQuantity, float, np.ndarray],
         baseline: bool = False,
-        ncl_id: Opt[int] = None,
+        ncl_id: Optional[int] = None,
         time_unit: str = "s",
         power_unit: str = "W",
     ) -> Union[float, np.ndarray]: