diff --git a/opm/core/simulator/BlackoilState.cpp b/opm/core/simulator/BlackoilState.cpp
index 02be96b8e..225567c2c 100644
--- a/opm/core/simulator/BlackoilState.cpp
+++ b/opm/core/simulator/BlackoilState.cpp
@@ -11,6 +11,7 @@ using namespace Opm;
 const std::string BlackoilState::GASOILRATIO = "GASOILRATIO";
 const std::string BlackoilState::RV = "RV";
 const std::string BlackoilState::SURFACEVOL = "SURFACEVOL";
+const std::string BlackoilState::SSOL = "SSOL";
 
 
 BlackoilState::BlackoilState( size_t num_cells , size_t num_faces , size_t num_phases)
@@ -19,6 +20,7 @@ BlackoilState::BlackoilState( size_t num_cells , size_t num_faces , size_t num_p
     registerCellData( GASOILRATIO , 1 );
     registerCellData( RV, 1 );
     registerCellData( SURFACEVOL, num_phases );
+    registerCellData( SSOL , 1 );
     setBlackoilStateReferencePointers();
 }
 
diff --git a/opm/core/simulator/BlackoilState.hpp b/opm/core/simulator/BlackoilState.hpp
index fe6c0dbc5..a5dc428ae 100644
--- a/opm/core/simulator/BlackoilState.hpp
+++ b/opm/core/simulator/BlackoilState.hpp
@@ -43,6 +43,7 @@ namespace Opm
         static const std::string GASOILRATIO;
         static const std::string RV;
         static const std::string SURFACEVOL;
+        static const std::string SSOL;
 
         /// Main constructor setting the sizes for the contained data
         /// types.