diff --git a/dune/solvers/iterationsteps/mmgstep.cc b/dune/solvers/iterationsteps/mmgstep.cc
index 3f8e97dcbdeb9beab1378e29c32100106c218d15..dd59802e9e9dcbe7da5a1443790e7002682c5c72 100644
--- a/dune/solvers/iterationsteps/mmgstep.cc
+++ b/dune/solvers/iterationsteps/mmgstep.cc
@@ -71,7 +71,7 @@ void MonotoneMGStep<MatrixType, VectorType>::nestedIteration()
         this->mgTransfer_[i-1]->restrict(this->rhsHierarchy_[i], this->rhsHierarchy_[i-1]);
     }
 
-    for (this->level_ = 0; this->level_<this->numLevels()-1; this->level_++) {
+    for (this->level_ = 0; this->level_<(int) this->numLevels()-1; this->level_++) {
 
         // If we start from an infeasible configuration, the restricted
         // obstacles may be inconsistent.  We do an ad hoc correction here.
@@ -239,7 +239,7 @@ void MonotoneMGStep<MatrixType, VectorType>::iterate()
     // ////////////////////////////////////////////////////////////////////
     //   Track the number of critical nodes found during this iteration
     // ////////////////////////////////////////////////////////////////////
-    if (level==this->numLevels()-1 && this->verbosity_==NumProc::FULL) {
+    if (level==(int) this->numLevels()-1 && this->verbosity_==NumProc::FULL) {
             
         std::cout << critical.count() << " critical nodes found on level " << level;
             
@@ -254,7 +254,7 @@ void MonotoneMGStep<MatrixType, VectorType>::iterate()
     }
 
     // Debug: output energy
-    if (level==this->numLevels()-1 && this->verbosity_==NumProc::FULL)
+    if (level==(int) this->numLevels()-1 && this->verbosity_==NumProc::FULL)
         std::cout << "Total energy: " 
                   << std::setprecision(10) << computeEnergy(*mat[level], *x[level], rhs[level]) << std::endl;
 
diff --git a/dune/solvers/iterationsteps/multigridstep.cc b/dune/solvers/iterationsteps/multigridstep.cc
index a9bf3f63bf7bdae48435925f0fe831fb2b351d05..0c2f09f1e8d369bb0ee08a86e2f532352c7dc0fc 100644
--- a/dune/solvers/iterationsteps/multigridstep.cc
+++ b/dune/solvers/iterationsteps/multigridstep.cc
@@ -184,7 +184,7 @@ else {
 template<class MatrixType, class VectorType, class BitVectorType>
 void MultigridStep<MatrixType, VectorType, BitVectorType>::nestedIteration()
 {
-    for (level_ = 0; level_<numLevels(); level_++)
+    for (level_ = 0; level_<(int) numLevels(); level_++)
     {
         iterate();