diff --git a/dune/istl/solver.hh b/dune/istl/solver.hh
index e16aab438a71100d979d3a8fb354f460518e739f..8ace9496b486558c489567bdfbbf8af0e844c7f0 100644
--- a/dune/istl/solver.hh
+++ b/dune/istl/solver.hh
@@ -3,6 +3,10 @@
 
 #ifndef DUNE_SOLVER_HH
 #define DUNE_SOLVER_HH
+
+#include <iomanip>
+#include <ostream>
+
 namespace Dune
 {
 /**