diff --git a/oommfc/drivers/hysteresisdriver.py b/oommfc/drivers/hysteresisdriver.py
index 17ff240..69a2fc5 100644
--- a/oommfc/drivers/hysteresisdriver.py
+++ b/oommfc/drivers/hysteresisdriver.py
@@ -73,7 +73,7 @@ def _checkargs(self, **kwargs):
         if n - 1 <= 0:  # OOMMF counts steps, not points (n -> n-1)
             msg = f"Cannot drive with {n=}."
             raise ValueError(msg)
-        
+
     def _check_system(self, system):
         """Checks the system has energy in it"""
         if len(system.energy) == 0: