diff --git a/dune/tectonic/myblockproblem.hh b/dune/tectonic/myblockproblem.hh
index 2c91cfbd0f2e19878ee3b9a44e128c42fd2119cc..a69f2a0b2585361258564ed07076dc9850eab860 100644
--- a/dune/tectonic/myblockproblem.hh
+++ b/dune/tectonic/myblockproblem.hh
@@ -182,8 +182,7 @@ template <class MyConvexProblemTypeTEMPLATE> class MyBlockProblem {
 
     // compute quadratic part of gradient
     linearization.b.resize(u.size());
-    linearization.b = 0.0;
-    problem.A.template umv<VectorType, VectorType>(u, linearization.b);
+    problem.A.mv(u, linearization.b);
     linearization.b -= problem.f;
 
     // compute nonlinearity part of gradient