diff --git a/dune/solvers/iterationsteps/multigridstep.cc b/dune/solvers/iterationsteps/multigridstep.cc
index 6d4d9c5350a4f6aaa694402f9646ea25cf42262a..87840d96125702fa03390aa8fc040dfcd646cb08 100644
--- a/dune/solvers/iterationsteps/multigridstep.cc
+++ b/dune/solvers/iterationsteps/multigridstep.cc
@@ -38,7 +38,7 @@ template<class OperatorType, class VectorType, class BitVectorType>
 void MultigridStep<OperatorType, VectorType, BitVectorType>::preprocess()
 {
     if(preprocessCalled)
-        std::cout << "Preprocess has already been called without calling iterate afterwards!" << std::endl;
+        std::cout << "Warning: Preprocess has already been called without calling iterate afterwards!" << std::endl;
     preprocessCalled = true;
 
     int i;