diff --git a/ebos/eclgenericoutputblackoilmodule.hh b/ebos/eclgenericoutputblackoilmodule.hh
index cbb9020fc..6005b570c 100644
--- a/ebos/eclgenericoutputblackoilmodule.hh
+++ b/ebos/eclgenericoutputblackoilmodule.hh
@@ -252,6 +252,12 @@ public:
     // Virtual destructor for safer inheritance.
     virtual ~EclGenericOutputBlackoilModule();
 
+    template<class Serializer>
+    void serializeOp(Serializer& serializer)
+    {
+        serializer(initialInplace_);
+    }
+
 protected:
     using ScalarBuffer = std::vector<Scalar>;
     using StringBuffer = std::vector<std::string>;
diff --git a/ebos/eclproblem.hh b/ebos/eclproblem.hh
index 4f124a64c..5277a8ce4 100644
--- a/ebos/eclproblem.hh
+++ b/ebos/eclproblem.hh
@@ -2060,6 +2060,7 @@ public:
         serializer(aquiferModel_);
         serializer(tracerModel_);
         serializer(*materialLawManager_);
+        serializer(*eclWriter_);
     }
 
 private:
diff --git a/ebos/eclwriter.hh b/ebos/eclwriter.hh
index 2ea89bcd9..021503219 100644
--- a/ebos/eclwriter.hh
+++ b/ebos/eclwriter.hh
@@ -475,6 +475,12 @@ public:
     Scalar restartTimeStepSize() const
     { return restartTimeStepSize_; }
 
+    template<class Serializer>
+    void serializeOp(Serializer& serializer)
+    {
+        serializer(*eclOutputModule_);
+    }
+
 private:
     static bool enableEclOutput_()
     { return EWOMS_GET_PARAM(TypeTag, bool, EnableEclOutput); }