diff --git a/dune/solvers/iterationsteps/mmgstep.hh b/dune/solvers/iterationsteps/mmgstep.hh
index a8bed74f90eab9c238025c5f4ffa7bf459f6f230..0fccf3b630600e5d4c35076f292575bd2a1de89f 100644
--- a/dune/solvers/iterationsteps/mmgstep.hh
+++ b/dune/solvers/iterationsteps/mmgstep.hh
@@ -43,6 +43,7 @@ public:
     {
         Base::setProblem(mat,x,rhs);
         oldCritical.resize(x.size(), false);
+        oldCritical.unsetAll();
     }
 
     virtual void iterate();