diff --git a/opm/parser/eclipse/EclipseState/EclipseState.hpp b/opm/parser/eclipse/EclipseState/EclipseState.hpp
index fa672507e..c9ad93032 100644
--- a/opm/parser/eclipse/EclipseState/EclipseState.hpp
+++ b/opm/parser/eclipse/EclipseState/EclipseState.hpp
@@ -122,8 +122,8 @@ namespace Opm {
             serializer(m_runspec);
             serializer(m_eclipseConfig);
             serializer(m_deckUnitSystem);
-            serializer(m_inputNnc);
-            serializer(m_inputEditNnc);
+            m_inputNnc.serializeOp(serializer);
+            m_inputEditNnc.serializeOp(serializer);
             serializer(m_gridDims);
             serializer(m_simulationConfig);
             serializer(m_transMult);
diff --git a/opm/parser/eclipse/EclipseState/Edit/EDITNNC.hpp b/opm/parser/eclipse/EclipseState/Edit/EDITNNC.hpp
index c85027555..105bb221e 100644
--- a/opm/parser/eclipse/EclipseState/Edit/EDITNNC.hpp
+++ b/opm/parser/eclipse/EclipseState/Edit/EDITNNC.hpp
@@ -46,6 +46,12 @@ public:
 
     bool operator==(const EDITNNC& data) const;
 
+    template<class Serializer>
+    void serializeOp(Serializer& serializer)
+    {
+        serializer.vector(m_editnnc);
+    }
+
 private:
     std::vector<NNCdata> m_editnnc;
 };
diff --git a/opm/parser/eclipse/EclipseState/Grid/NNC.hpp b/opm/parser/eclipse/EclipseState/Grid/NNC.hpp
index c08d53e28..1c5099dfb 100644
--- a/opm/parser/eclipse/EclipseState/Grid/NNC.hpp
+++ b/opm/parser/eclipse/EclipseState/Grid/NNC.hpp
@@ -40,6 +40,14 @@ struct NNCdata {
                trans == data.trans;
     }
 
+    template<class Serializer>
+    void serializeOp(Serializer& serializer)
+    {
+        serializer(cell1);
+        serializer(cell2);
+        serializer(trans);
+    }
+
     size_t cell1;
     size_t cell2;
     double trans;
@@ -64,6 +72,12 @@ public:
 
     bool operator==(const NNC& data) const;
 
+    template<class Serializer>
+    void serializeOp(Serializer& serializer)
+    {
+        serializer.vector(m_nnc);
+    }
+
 private:
 
     std::vector<NNCdata> m_nnc;