diff --git a/opm/parser/eclipse/EclipseState/Schedule/CompletedCells.hpp b/opm/parser/eclipse/EclipseState/Schedule/CompletedCells.hpp
index 9ecf63bf8..d3e790fbb 100644
--- a/opm/parser/eclipse/EclipseState/Schedule/CompletedCells.hpp
+++ b/opm/parser/eclipse/EclipseState/Schedule/CompletedCells.hpp
@@ -51,6 +51,27 @@ public:
                        this->ntg == other.ntg;
             }
 
+            template<class Serializer>
+            void serializeOp(Serializer& serializer)
+            {
+                serializer(this->permx);
+                serializer(this->permy);
+                serializer(this->permz);
+                serializer(this->satnum);
+                serializer(this->pvtnum);
+                serializer(this->ntg);
+            }
+
+            static Props serializeObject(){
+                Props props;
+                props.permx = 10.0;
+                props.permy = 78.0;
+                props.permz = 45.4;
+                props.satnum = 3;
+                props.pvtnum = 5;
+                props.ntg = 45.1;
+                return props;
+            }
         };
 
         std::optional<Props> props;