diff --git a/dune/tectonic/myblockproblem.hh b/dune/tectonic/myblockproblem.hh
index 842bd73b3f69c9947588a6d2d247c6370ba55221..3b4a8ff507e7f4bd7571d54beb38626322d35f86 100644
--- a/dune/tectonic/myblockproblem.hh
+++ b/dune/tectonic/myblockproblem.hh
@@ -120,6 +120,7 @@ class MyBlockProblem<MyConvexProblemTypeTEMPLATE>::IterateObject {
 
       LocalVectorType correction;
       Dune::minimise(localJ, ui, 5, bisection); // FIXME: hardcoded value
+      free(f);
     }
   }