diff --git a/LDDsimulation.py b/LDDsimulation.py
index 1a0d6c9c7465ae323ab080ac1cc38c849c639120..4f2e9964893588e66349ca2c4bfce27791687cc5 100644
--- a/LDDsimulation.py
+++ b/LDDsimulation.py
@@ -97,7 +97,8 @@ class LDDsimulation(object):
                        viscosity: tp.Dict[int, tp.List[float]],#
                        porosity: tp.Dict[int, float],#
                        L: tp.Dict[int, tp.List[float]],#
-                       lambda_param: tp.Dict[int, tp.List[float]])-> None:
+                       lambda_param: tp.Dict[int, tp.List[float]],#
+                       relative_permeability: tp.Dict[int, tp.Callable[...,None]])-> None:
         """ set parameters of an instance of class LDDsimulation"""
         self.output_dir = output_dir
         self.subdomain_def_points = subdomain_def_points
@@ -109,6 +110,7 @@ class LDDsimulation(object):
         self.porosity = porosity
         self.L = L
         self.lambda_param = lambda_param
+        self.relative_permeability = relative_permeability
         self._parameters_set = True
 
     def initialise(self) -> None:
@@ -255,9 +257,11 @@ class LDDsimulation(object):
                     mesh = self.mesh_subdomain[subdom_num],#
                     viscosity = self.viscosity[subdom_num],#
                     porosity = self.porosity[subdom_num],#
+                    interfaces = self.interface,#
                     has_interface = interface_list,#
                     L = self.L[subdom_num],#
-                    lambda_param = self.lambda_param[subdom_num]#
+                    lambda_param = self.lambda_param[subdom_num],#
+                    relative_permeability = self.relative_permeability[subdom_num]#
                     ))