diff --git a/src/daemon/MoneroDaemonModel.cpp b/src/daemon/MoneroDaemonModel.cpp
index 2c551bd..01aa53d 100644
--- a/src/daemon/MoneroDaemonModel.cpp
+++ b/src/daemon/MoneroDaemonModel.cpp
@@ -80,6 +80,10 @@ namespace monero {
     return node;
   }
 
+  void MoneroBlock::merge(const shared_ptr<MoneroBlockHeader>& self, const shared_ptr<MoneroBlockHeader>& other) {
+    merge(static_pointer_cast<MoneroBlock>(self), static_pointer_cast<MoneroBlock>(other));
+  }
+
   void MoneroBlock::merge(const shared_ptr<MoneroBlock>& self, const shared_ptr<MoneroBlock>& other) {
     if (this != self.get()) throw runtime_error("this != self");
     if (self == other) return;
diff --git a/src/daemon/MoneroDaemonModel.h b/src/daemon/MoneroDaemonModel.h
index fc3b762..20c69e3 100644
--- a/src/daemon/MoneroDaemonModel.h
+++ b/src/daemon/MoneroDaemonModel.h
@@ -82,7 +82,7 @@ namespace monero {
     boost::optional<string> powHash;
 
     boost::property_tree::ptree toPropertyTree() const;
-    void merge(const shared_ptr<MoneroBlockHeader>& self, const shared_ptr<MoneroBlockHeader>& other);
+    virtual void merge(const shared_ptr<MoneroBlockHeader>& self, const shared_ptr<MoneroBlockHeader>& other);
   };
 
   /**
@@ -95,6 +95,7 @@ namespace monero {
     vector<string> txIds;
 
     boost::property_tree::ptree toPropertyTree() const;
+    void merge(const shared_ptr<MoneroBlockHeader>& self, const shared_ptr<MoneroBlockHeader>& other);
     void merge(const shared_ptr<MoneroBlock>& self, const shared_ptr<MoneroBlock>& other);
   };
 
@@ -144,7 +145,7 @@ namespace monero {
 
     boost::property_tree::ptree toPropertyTree() const;
     boost::optional<uint64_t> getHeight() const;
-    void merge(const shared_ptr<MoneroTx>& self, const shared_ptr<MoneroTx>& other);
+    virtual void merge(const shared_ptr<MoneroTx>& self, const shared_ptr<MoneroTx>& other) ;
   };
 
   /**
@@ -170,6 +171,6 @@ namespace monero {
     boost::optional<string> stealthPublicKey;
 
     boost::property_tree::ptree toPropertyTree() const;
-    void merge(const shared_ptr<MoneroOutput>& self, const shared_ptr<MoneroOutput>& other);
+    virtual void merge(const shared_ptr<MoneroOutput>& self, const shared_ptr<MoneroOutput>& other);
   };
 }
diff --git a/src/wallet/MoneroWalletModel.cpp b/src/wallet/MoneroWalletModel.cpp
index 09a7c7c..fcad796 100644
--- a/src/wallet/MoneroWalletModel.cpp
+++ b/src/wallet/MoneroWalletModel.cpp
@@ -74,6 +74,11 @@ namespace monero {
     return !incomingTransfers.empty();
   }
 
+  void MoneroTxWallet::merge(const shared_ptr<MoneroTx>& self, const shared_ptr<MoneroTx>& other) {
+    cout << "MoneroTxWallet::merge(MoneroTx&, MoneroTx&)" << endl;
+    merge(static_pointer_cast<MoneroTxWallet>(self), static_pointer_cast<MoneroTxWallet>(other));
+  }
+
   void MoneroTxWallet::merge(const shared_ptr<MoneroTxWallet>& self, const shared_ptr<MoneroTxWallet>& other) {
     cout << "MoneroTxWallet::merge()" << endl;
     if (this != self.get()) throw runtime_error("this != self");
@@ -382,11 +387,6 @@ namespace monero {
     return node;
   }
 
-  void MoneroOutputWallet::merge(const shared_ptr<MoneroOutputWallet>& self, const shared_ptr<MoneroOutputWallet>& other) {
-    cout << "MoneroOutputWallet::merge()" << endl;
-    throw runtime_error("not implemented");
-  }
-
   // ------------------------ MONERO OUTPUT REQUEST ---------------------------
 
   boost::property_tree::ptree MoneroOutputRequest::toPropertyTree() const {
diff --git a/src/wallet/MoneroWalletModel.h b/src/wallet/MoneroWalletModel.h
index d71f65e..20301f7 100644
--- a/src/wallet/MoneroWalletModel.h
+++ b/src/wallet/MoneroWalletModel.h
@@ -102,7 +102,7 @@ namespace monero {
       return !(*getIsIncoming());
     }
     boost::property_tree::ptree toPropertyTree() const;
-    void merge(const shared_ptr<MoneroTransfer>& self, const shared_ptr<MoneroTransfer>& other);
+    virtual void merge(const shared_ptr<MoneroTransfer>& self, const shared_ptr<MoneroTransfer>& other);
   };
 
   /**
@@ -161,7 +161,6 @@ namespace monero {
     boost::optional<bool> isFrozen;
 
     boost::property_tree::ptree toPropertyTree() const;
-    void merge(const shared_ptr<MoneroOutputWallet>& self, const shared_ptr<MoneroOutputWallet>& other);
   };
 
   /**
@@ -189,6 +188,7 @@ namespace monero {
     bool getIsIncoming() const;
     bool getIsOutgoing() const;
     boost::property_tree::ptree toPropertyTree() const;
+    void merge(const shared_ptr<MoneroTx>& self, const shared_ptr<MoneroTx>& other);
     void merge(const shared_ptr<MoneroTxWallet>& self, const shared_ptr<MoneroTxWallet>& other);
   };