diff --git a/LDDsimulation/LDDsimulation.py b/LDDsimulation/LDDsimulation.py
index 95138cf5700e63d4989f492106faac9458460a39..8161e99fb58bcaad27d4d57be238e3c889b6ff12 100644
--- a/LDDsimulation/LDDsimulation.py
+++ b/LDDsimulation/LDDsimulation.py
@@ -924,13 +924,13 @@ class LDDsimulation(object):
             # overwrite what has been set by init()
             self.adjacent_subdomains = adjacent_subdomains
         interface_of_subdomain =[]
-        for interface_ind, adj_doms in enumerate(adjacent_subdomains):
+        for global_interface_ind, adj_doms in enumerate(adjacent_subdomains):
             # interface [i,j] and [j,i] are not counted seperately in adjacent_subdomains
             # therefor we don't care wether subdomain_index == adj_doms[0] or
             # subdomain_index == adj_doms[1]. if subdomain_index is one of either,
             # the interface belongs to the subdomain with this index.
             if np.isin(subdomain_index, adj_doms, assume_unique=True):
-                interface_of_subdomain.append(interface_ind)
+                interface_of_subdomain.append(global_interface_ind)
 
         return interface_of_subdomain