diff --git a/src/MempoolStatus.cpp b/src/MempoolStatus.cpp
index 928e5bb..61e23ed 100644
--- a/src/MempoolStatus.cpp
+++ b/src/MempoolStatus.cpp
@@ -170,7 +170,7 @@ MempoolStatus::read_mempool()
         vector<txin_to_key> input_key_imgs;
 
         // public keys and xmr amount of outputs
-        vector<tuple<public_key, uint64_t, view_tag>> output_pub_keys;
+        vector<output_tuple_with_tag> output_pub_keys;
 
         // sum xmr in inputs and ouputs in the given tx
         const array<uint64_t, 4>& sum_data = summary_of_in_out_rct(
diff --git a/src/page.h b/src/page.h
index 99e8dd7..d06b671 100644
--- a/src/page.h
+++ b/src/page.h
@@ -336,7 +336,7 @@ struct tx_details
     vector<txin_to_key> input_key_imgs;
 
     // public keys and xmr amount of outputs
-    vector<tuple<public_key, uint64_t, view_tag>> output_pub_keys;
+    vector<output_tuple_with_tag> output_pub_keys;
 
     mstch::map
     get_mstch_map() const
@@ -2181,7 +2181,7 @@ show_my_outputs(string tx_hash_str,
 
     uint64_t output_idx {0};
 
-    for (tuple<public_key, uint64_t, view_tag>& outp: txd.output_pub_keys)
+    for (output_tuple_with_tag& outp: txd.output_pub_keys)
     {
 
         // get the tx output public key
@@ -4236,9 +4236,9 @@ search_txs(vector<transaction> txs, const string& search_text)
 
         // check if output_public_keys matche the search_text
 
-        vector<tuple<public_key, uint64_t, view_tag>>::iterator it2 =
+        vector<output_tuple_with_tag>::iterator it2 =
                 find_if(begin(txd.output_pub_keys), end(txd.output_pub_keys),
-                        [&](const tuple<public_key, uint64_t, view_tag>& tx_out_pk)
+                        [&](const output_tuple_with_tag& tx_out_pk)
                         {
                             return pod_to_hex(std::get<0>(tx_out_pk)) == search_text;
                         });
@@ -5387,7 +5387,7 @@ json_outputs(string tx_hash_str,
     j_data["outputs"] = json::array();
     json& j_outptus   = j_data["outputs"];
 
-    for (tuple<public_key, uint64_t, view_tag>& outp: txd.output_pub_keys)
+    for (output_tuple_with_tag& outp: txd.output_pub_keys)
     {
 
         // get the tx output public key
@@ -5863,7 +5863,7 @@ find_our_outputs(
         //j_data["outputs"] = json::array();
         //json& j_outptus   = j_data["outputs"];
 
-        for (tuple<public_key, uint64_t, view_tag> &outp: txd.output_pub_keys)
+        for (output_tuple_with_tag &outp: txd.output_pub_keys)
         {
 
             // get the tx output public key
@@ -6456,7 +6456,7 @@ construct_tx_context(transaction tx, uint16_t with_ring_signatures = 0)
 
     uint64_t outputs_xmr_sum {0};
 
-    for (tuple<public_key, uint64_t, view_tag>& outp: txd.output_pub_keys)
+    for (output_tuple_with_tag& outp: txd.output_pub_keys)
     {
 
         // total number of ouputs in the blockchain for this amount
@@ -6476,7 +6476,12 @@ construct_tx_context(transaction tx, uint16_t with_ring_signatures = 0)
         outputs_xmr_sum += std::get<1>(outp);
 
         std::stringstream ss;
-        ss << std::get<2>(outp);
+        if (std::get<2>(outp)) {
+            ss << *(std::get<2>(outp));
+        }
+        else {
+          ss << "-";
+        }
         string view_tag_str = ss.str();
 
 
diff --git a/src/tools.cpp b/src/tools.cpp
index 1923335..0340552 100644
--- a/src/tools.cpp
+++ b/src/tools.cpp
@@ -345,7 +345,7 @@ sum_money_in_outputs(const json& _json)
 array<uint64_t, 4>
 summary_of_in_out_rct(
         const transaction& tx,
-        vector<tuple<public_key, uint64_t, view_tag>>& output_pub_keys,
+        vector<output_tuple_with_tag>& output_pub_keys,
         vector<txin_to_key>& input_key_imgs)
 {
 
@@ -361,17 +361,24 @@ summary_of_in_out_rct(
         if (!cryptonote::get_output_public_key(txout, output_pub_key))
         {
             // push empty pair.
-            output_pub_keys.push_back(tuple<public_key, uint64_t, view_tag>{});
+            output_pub_keys.push_back(output_tuple_with_tag {
+                                        public_key{},
+                                        uint64_t{},
+                                        boost::none
+                              });
             continue;
         }
 
-        view_tag output_tag {};
+        boost::optional<view_tag> output_tag;
 
          if (txout.target.type() == typeid(txout_to_tagged_key)) {
              output_tag =  boost::get< txout_to_tagged_key >(txout.target).view_tag;
          }
 
-        output_pub_keys.push_back(make_tuple(output_pub_key, txout.amount, output_tag));
+        output_pub_keys.push_back(
+                    make_tuple(output_pub_key,
+                               txout.amount,
+                               output_tag));
 
         xmr_outputs += txout.amount;
     }
@@ -622,28 +629,35 @@ sum_fees_in_txs(const vector<transaction>& txs)
 
 
 
-vector<tuple<public_key, uint64_t, view_tag>>
+vector<output_tuple_with_tag>
 get_ouputs(const transaction& tx)
 {
-    vector<tuple<public_key, uint64_t, view_tag>> outputs;
+    vector<output_tuple_with_tag> outputs;
 
     for (const tx_out& txout: tx.vout)
     {
         public_key output_pub_key;
         if (!cryptonote::get_output_public_key(txout, output_pub_key))
         {
-            // push empty pair.
-            outputs.push_back(tuple<public_key, uint64_t, view_tag>{});
+            // push empty tuple.
+            outputs.push_back(output_tuple_with_tag {
+                                        public_key{},
+                                        uint64_t{},
+                                        boost::none
+                              });
             continue;
         }
 
-        view_tag output_tag {};
+         boost::optional<view_tag> output_tag;
 
          if (txout.target.type() == typeid(txout_to_tagged_key)) {
-             output_tag =  boost::get< txout_to_tagged_key >(txout.target).view_tag;
+             output_tag =  boost::get< txout_to_tagged_key >(txout.target)
+                                    .view_tag;
          }
 
-        outputs.push_back(make_tuple(output_pub_key, txout.amount, output_tag));
+        outputs.push_back(make_tuple(output_pub_key,
+                                     txout.amount,
+                                     output_tag));
     }
 
     return outputs;
diff --git a/src/tools.h b/src/tools.h
index 1db46cb..164d2a1 100644
--- a/src/tools.h
+++ b/src/tools.h
@@ -49,6 +49,10 @@ namespace bf = boost::filesystem;
 
 using json = nlohmann::json;
 
+using output_tuple_with_tag = tuple<public_key,
+                              uint64_t,
+                              boost::optional<view_tag>>;
+
 struct outputs_visitor
 {
     std::vector<crypto::public_key >& m_output_keys;
@@ -154,7 +158,7 @@ sum_money_in_outputs(const json& _json);
 array<uint64_t, 4>
 summary_of_in_out_rct(
         const transaction& tx,
-        vector<tuple<public_key, uint64_t, view_tag>>& output_pub_keys,
+        vector<output_tuple_with_tag>& output_pub_keys,
         vector<txin_to_key>& input_key_imgs);
 
 // this version for mempool txs from json
@@ -200,7 +204,7 @@ get_mixin_no(const json& _json);
 vector<uint64_t>
 get_mixin_no_in_txs(const vector<transaction>& txs);
 
-vector<tuple<public_key, uint64_t, view_tag>>
+vector<output_tuple_with_tag>
 get_ouputs(const transaction& tx);
 
 vector<tuple<public_key, uint64_t, uint64_t>>