diff --git a/tutorials/poisson_overlap/main.cpp b/tutorials/poisson_overlap/main.cpp
index bb5c0b764bac3665736b62f41cd970b40cd24de6..fd2474aa0af7a6258dc064c5dddbe8518dc7985b 100644
--- a/tutorials/poisson_overlap/main.cpp
+++ b/tutorials/poisson_overlap/main.cpp
@@ -51,11 +51,11 @@ int main(int argc, char **argv)
 
   Subdomain omega(nDom);
   Interface sigma(nDom);
-  omega(0) = left | center;
-  omega(1) = center | right;
+  omega(0) = gammaLeft | left | interface1 | center;
+  omega(1) = gammaRight | center | interface2 | right;
 
-  sigma(0, 1) = center;
-  sigma(1, 0) = center;
+  sigma(0, 1) = interface1 | interface2;
+  sigma(1, 0) = interface2 | interface1;
 
   std::vector< std::vector< unsigned int > > topology(nDom);
   topology[0] = {1};