diff --git a/dune/tectonic/myblockproblem.hh b/dune/tectonic/myblockproblem.hh
index f226fd70a8eaecaa6b3e0672cc44a4ace1b69d3f..2005947f1fd6af2d53e3d8a1a4f2e3d9247a4c0a 100644
--- a/dune/tectonic/myblockproblem.hh
+++ b/dune/tectonic/myblockproblem.hh
@@ -76,7 +76,11 @@ template <class MyConvexProblemTypeTEMPLATE> class MyBlockProblem {
                                Linearization const &linearization) const {
     // TODO: implement (not urgent)
     projected_v = v;
-  };
+    for (size_t i = 0; i < v.size(); ++i)
+      for (int j = 0; j < block_size; ++j)
+        if (linearization.truncation[i][j])
+          projected_v[i][j] = 0;
+  }
 
   double computeDampingParameter(VectorType const &u,
                                  VectorType const &projected_v) const {