diff --git a/benchmarks/testsuite/linkrods.geo b/benchmarks/testsuite/linkrods.geo
index 9cbde835cbb6fd4210005da0851508552ce5592f..6db316afea6d65b7b1992985ee2f9227b5f72465 100644
--- a/benchmarks/testsuite/linkrods.geo
+++ b/benchmarks/testsuite/linkrods.geo
@@ -6,6 +6,7 @@ Merge "linkrods.step";
 Surface Loop(1) = {25,24,23,21,28,26,36,9,2,4,5,6,3,1,7,18,17,8,10,16,15,12,14,37,34,13,11,35,31,33,32,30,29,27,19,20,22};
 Volume(2) = {1};
 //Mesh.RefineSteps=16;
-Function Field(1) = "Cos(2*3.14*(x+y-z))*.05 + .06";
-Characteristic Length Field{1};
+Field[1] = MathEval;
+Field[1].F = "Cos(2*3.14*(x+y-z))*.05 + .06";
+Background Field = 1;
 Mesh.CharacteristicLengthFactor=1;