diff --git a/dune/tectonic/myblockproblem.hh b/dune/tectonic/myblockproblem.hh
index e34a194322ce56eb622fc16fb8bc60d1ea2ec995..1cf7ede03ff2480e41d259a047a374bfe5da9cc8 100644
--- a/dune/tectonic/myblockproblem.hh
+++ b/dune/tectonic/myblockproblem.hh
@@ -94,7 +94,7 @@ template <class MyConvexProblemTypeTEMPLATE> class MyBlockProblem {
       localA = <Av,v>
       localb = <b - Au, v>
     */
-    MyDirectionalConvexFunction<Dune::GlobalNonlinearity<block_size>> psi(
+    MyDirectionalConvexFunction<Dune::GlobalNonlinearity<block_size>> const psi(
         localA, localb, problem.phi, u, v);
 
     int bisectionsteps = 0;