diff --git a/examples/poiseuille_flow_channel_shear_thinning.py b/examples/poiseuille_flow_channel_shear_thinning.py
index 23cc508..f9068f0 100644
--- a/examples/poiseuille_flow_channel_shear_thinning.py
+++ b/examples/poiseuille_flow_channel_shear_thinning.py
@@ -288,7 +288,7 @@ def compute_quality_criterion(
 def calculate_reward(
     quality_criterions: np.ndarray,
     last_quality_criterions: np.ndarray,
-    **kwargs
+    **kwargs,
 ) -> float:
     """Function that actually calculates the reward.