diff --git a/dune/solvers/iterationsteps/projectedlinegsstep.cc b/dune/solvers/iterationsteps/projectedlinegsstep.cc
index dfc08e60717fc913b7c931942352998d9008af59..7560df3801cdaf41abdfb88caf6ee2017f86c487 100755
--- a/dune/solvers/iterationsteps/projectedlinegsstep.cc
+++ b/dune/solvers/iterationsteps/projectedlinegsstep.cc
@@ -1,6 +1,7 @@
 #include <dune/istl/scaledidmatrix.hh>
 
 #include <dune/solvers/iterationsteps/projectedblockgsstep.hh>
+#include <dune/solvers/norms/energynorm.hh>
 
 template<class MatrixType, class VectorType, class BitVectorType>
 void ProjectedLineGSStep<MatrixType, VectorType, BitVectorType >::