diff --git a/src/nomad_simulations/schema_packages/properties/forces.py b/src/nomad_simulations/schema_packages/properties/forces.py
index d299bd71..5ac6879a 100644
--- a/src/nomad_simulations/schema_packages/properties/forces.py
+++ b/src/nomad_simulations/schema_packages/properties/forces.py
@@ -48,6 +48,7 @@
 from nomad_simulations.schema_packages.physical_property import (
     PhysicalProperty,
     PropertyContribution,
+)
 
 ####################################################
 # Abstract force classes