diff --git a/src/lbmpy/boundaries/boundaryconditions.py b/src/lbmpy/boundaries/boundaryconditions.py
index e49edca1c980b90f592b041100ab1a20cc4fe633..b1801b894b717fc95d38670819a46535ec79e06b 100644
--- a/src/lbmpy/boundaries/boundaryconditions.py
+++ b/src/lbmpy/boundaries/boundaryconditions.py
@@ -1025,8 +1025,8 @@ class iMEMBounceBack(LbBoundary):
 
         weight_info = LbmWeightInfo(lb_method, data_type=self.data_type)
         weight_of_direction = weight_info.weight_of_direction
-        f_ijk_uw = 2 / (c_s_sq*(1+q)) * rho * weight_of_direction( dir_symbol, lb_method) * 
-                                sum([d_i * v_i for d_i, v_i in zip(neighbor_offset, velocity)]) 
+        f_ijk_uw = 2 / (c_s_sq*(1+q)) * rho * weight_of_direction( dir_symbol, lb_method) * \
+                                sum([d_i * v_i for d_i, v_i in zip(neighbor_offset, velocity)])
 
     # Step 6: Return Assignment
         # Eq. 20 in Asmuth2021: Note, eq. 20 should not have the 2x on LHS and should be - not +