diff --git a/dune/solvers/iterationsteps/projectedblockgsstep.cc b/dune/solvers/iterationsteps/projectedblockgsstep.cc
index e1932420e3f38cb91904620bacb5833453447ba6..1f76e4488c43a53b44c5c99db8dd461732045772 100644
--- a/dune/solvers/iterationsteps/projectedblockgsstep.cc
+++ b/dune/solvers/iterationsteps/projectedblockgsstep.cc
@@ -5,7 +5,7 @@ template<class MatrixType, class VectorType>
 inline
 void ProjectedBlockGSStep<MatrixType, VectorType>::iterate()
 {
-	assert(hasObstacle_!=nullptr);
+    assert(hasObstacle_!=nullptr);
 	
     if (hasObstacle_->size()!= (unsigned int)this->x_->size())
         DUNE_THROW(SolverError, "Size of hasObstacle (" << hasObstacle_->size()