diff --git a/opm/core/transport/implicit/ImplicitTransport.hpp b/opm/core/transport/implicit/ImplicitTransport.hpp
index 3bdd812..b775575 100644
--- a/opm/core/transport/implicit/ImplicitTransport.hpp
+++ b/opm/core/transport/implicit/ImplicitTransport.hpp
@@ -38,6 +38,8 @@
 
 #include <opm/core/transport/implicit/ImplicitAssembly.hpp>
 
+#include <iostream>
+
 namespace Opm {
     namespace ImplicitTransportDetails {
         struct NRControl {
diff --git a/opm/core/transport/implicit/TransportSolverTwophaseImplicit.cpp b/opm/core/transport/implicit/TransportSolverTwophaseImplicit.cpp
index c43aeb2..cb42191 100644
--- a/opm/core/transport/implicit/TransportSolverTwophaseImplicit.cpp
+++ b/opm/core/transport/implicit/TransportSolverTwophaseImplicit.cpp
@@ -34,6 +34,8 @@
 #include <opm/core/simulator/TwophaseState.hpp>
 #include <opm/core/utility/miscUtilities.hpp>
 
+#include <iostream>
+
 namespace Opm
 {