diff --git a/dune/solvers/iterationsteps/projectedblockgsstep.hh b/dune/solvers/iterationsteps/projectedblockgsstep.hh
index 3a9a287ed48fb250b13bd0b6b3ed38cec037a20b..111b093078a88d1caf3644e8507838cd1ce7b69a 100644
--- a/dune/solvers/iterationsteps/projectedblockgsstep.hh
+++ b/dune/solvers/iterationsteps/projectedblockgsstep.hh
@@ -8,6 +8,7 @@
 #include <dune/solvers/common/boxconstraint.hh>
 
 #include <dune/solvers/common/arithmetic.hh>
+#include <dune/solvers/iterationsteps/lineariterationstep.hh>
 
 template<class MatrixType, class VectorType>
 class ProjectedBlockGSStep : public LinearIterationStep<MatrixType, VectorType>