diff --git a/src/psimpy/simulator/mass_point_model.py b/src/psimpy/simulator/mass_point_model.py
index 5d3e14e5a0236ea7f09d003c2a35b57b82ea5770..7a1dd49db8cdd7d66ce54c342065ea36380e1947 100644
--- a/src/psimpy/simulator/mass_point_model.py
+++ b/src/psimpy/simulator/mass_point_model.py
@@ -8,6 +8,8 @@ from typing import Union
 from beartype import beartype
 
 class MassPointModel:
+
+    """Simulate the movement of a masspoint on a topography."""
     
     @staticmethod
     def _preprocess(elevation, x0, y0):