diff --git a/benchmarks/extrude/cylinder_double_boundary_layer.geo b/benchmarks/extrude/cylinder_double_boundary_layer.geo
index 8e67b5d03810eb8dc8afc8ea532172618c98a1f1..296e91c037c01a3e83378510b66f87eb222b364e 100644
--- a/benchmarks/extrude/cylinder_double_boundary_layer.geo
+++ b/benchmarks/extrude/cylinder_double_boundary_layer.geo
@@ -26,12 +26,15 @@ For iLine In {1:4}
 	Transfinite Line{iLine} = nb_pts_edge;
 EndFor
 
-Line Loop(1) = {1,2,3,4};
-Plane Surface(1) = {1};
+out[] = Extrude{0, 0, L}{Line{1:4}; Layers{nb_layers};};
 
-out[] = Extrude{0, 0, L}{Surface{1}; Layers{nb_layers};};
-
-Extrude { Surface{13,17,21,25}; Layers{5, 0.1}; Recombine; Using Index[0]; }
-Extrude { Surface{-13,-17,-21,-25}; Layers{5, 0.1}; Recombine; Using Index[1]; }
+Extrude { Surface{out[{1, 5, 9, 13}]}; Layers{5, 0.1}; Recombine; Using Index[0]; }
+Extrude { Surface{- out[{1, 5, 9, 13}]}; Layers{5, 0.1}; Recombine; Using Index[1]; }
 
 
+Line Loop(197) = {132, 154, 176, 110};
+Plane Surface(198) = {197};
+Line Loop(199) = {134, 112, 178, 156};
+Plane Surface(200) = {199};
+Surface Loop(201) = {200, 152, 174, 196, 130, 198};
+Volume(202) = {201};