diff --git a/src/bench/rpc_mempool.cpp b/src/bench/rpc_mempool.cpp
--- a/src/bench/rpc_mempool.cpp
+++ b/src/bench/rpc_mempool.cpp
@@ -46,4 +46,4 @@
     }
 }
 
-BENCHMARK(RpcMempool, 3);
+BENCHMARK(RpcMempool, 6);
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -484,23 +484,26 @@
     AssertLockHeld(pool.cs);
 
     UniValue fees(UniValue::VOBJ);
-    fees.pushKV("base", ValueFromAmount(e.GetFee()));
-    fees.pushKV("modified", ValueFromAmount(e.GetModifiedFee()));
-    fees.pushKV("ancestor", ValueFromAmount(e.GetModFeesWithAncestors()));
-    fees.pushKV("descendant", ValueFromAmount(e.GetModFeesWithDescendants()));
-    info.pushKV("fees", fees);
-
-    info.pushKV("size", (int)e.GetTxSize());
-    info.pushKV("fee", ValueFromAmount(e.GetFee()));
-    info.pushKV("modifiedfee", ValueFromAmount(e.GetModifiedFee()));
-    info.pushKV("time", e.GetTime());
-    info.pushKV("height", (int)e.GetHeight());
-    info.pushKV("descendantcount", e.GetCountWithDescendants());
-    info.pushKV("descendantsize", e.GetSizeWithDescendants());
-    info.pushKV("descendantfees", e.GetModFeesWithDescendants() / SATOSHI);
-    info.pushKV("ancestorcount", e.GetCountWithAncestors());
-    info.pushKV("ancestorsize", e.GetSizeWithAncestors());
-    info.pushKV("ancestorfees", e.GetModFeesWithAncestors() / SATOSHI);
+    fees.pushKV("base", ValueFromAmount(e.GetFee()), false);
+    fees.pushKV("modified", ValueFromAmount(e.GetModifiedFee()), false);
+    fees.pushKV("ancestor", ValueFromAmount(e.GetModFeesWithAncestors()),
+                false);
+    fees.pushKV("descendant", ValueFromAmount(e.GetModFeesWithDescendants()),
+                false);
+    info.pushKV("fees", fees, false);
+
+    info.pushKV("size", (int)e.GetTxSize(), false);
+    info.pushKV("fee", ValueFromAmount(e.GetFee()), false);
+    info.pushKV("modifiedfee", ValueFromAmount(e.GetModifiedFee()), false);
+    info.pushKV("time", e.GetTime(), false);
+    info.pushKV("height", (int)e.GetHeight(), false);
+    info.pushKV("descendantcount", e.GetCountWithDescendants(), false);
+    info.pushKV("descendantsize", e.GetSizeWithDescendants(), false);
+    info.pushKV("descendantfees", e.GetModFeesWithDescendants() / SATOSHI,
+                false);
+    info.pushKV("ancestorcount", e.GetCountWithAncestors(), false);
+    info.pushKV("ancestorsize", e.GetSizeWithAncestors(), false);
+    info.pushKV("ancestorfees", e.GetModFeesWithAncestors() / SATOSHI, false);
     const CTransaction &tx = e.GetTx();
     std::set<std::string> setDepends;
     for (const CTxIn &txin : tx.vin) {
@@ -514,7 +517,7 @@
         depends.push_back(dep);
     }
 
-    info.pushKV("depends", depends);
+    info.pushKV("depends", depends, false);
 
     UniValue spent(UniValue::VARR);
     const CTxMemPool::txiter &it = pool.mapTx.find(tx.GetId());
@@ -523,7 +526,7 @@
         spent.push_back(childiter->GetTx().GetId().ToString());
     }
 
-    info.pushKV("spentby", spent);
+    info.pushKV("spentby", spent, false);
 }
 
 UniValue MempoolToJSON(const CTxMemPool &pool, bool verbose) {
@@ -534,7 +537,7 @@
             const uint256 &txid = e.GetTx().GetId();
             UniValue info(UniValue::VOBJ);
             entryToJSON(pool, info, e);
-            o.pushKV(txid.ToString(), info);
+            o.pushKV(txid.ToString(), info, false);
         }
         return o;
     } else {
diff --git a/src/univalue/include/univalue.h b/src/univalue/include/univalue.h
--- a/src/univalue/include/univalue.h
+++ b/src/univalue/include/univalue.h
@@ -112,34 +112,34 @@
     bool push_backV(const std::vector<UniValue>& vec);
 
     void __pushKV(const std::string& key, const UniValue& val);
-    bool pushKV(const std::string& key, const UniValue& val);
-    bool pushKV(const std::string& key, const std::string& val_) {
+    bool pushKV(const std::string& key, const UniValue& val, bool checkForDuplicates = true);
+    bool pushKV(const std::string& key, const std::string& val_, bool checkForDuplicates = true) {
         UniValue tmpVal(VSTR, val_);
-        return pushKV(key, tmpVal);
+        return pushKV(key, tmpVal, checkForDuplicates);
     }
-    bool pushKV(const std::string& key, const char *val_) {
+    bool pushKV(const std::string& key, const char *val_, bool checkForDuplicates = true) {
         std::string _val(val_);
-        return pushKV(key, _val);
+        return pushKV(key, _val, checkForDuplicates);
     }
-    bool pushKV(const std::string& key, int64_t val_) {
+    bool pushKV(const std::string& key, int64_t val_, bool checkForDuplicates = true) {
         UniValue tmpVal(val_);
-        return pushKV(key, tmpVal);
+        return pushKV(key, tmpVal, checkForDuplicates);
     }
-    bool pushKV(const std::string& key, uint64_t val_) {
+    bool pushKV(const std::string& key, uint64_t val_, bool checkForDuplicates = true) {
         UniValue tmpVal(val_);
-        return pushKV(key, tmpVal);
+        return pushKV(key, tmpVal, checkForDuplicates);
     }
-    bool pushKV(const std::string& key, bool val_) {
+    bool pushKV(const std::string& key, bool val_, bool checkForDuplicates = true) {
         UniValue tmpVal((bool)val_);
-        return pushKV(key, tmpVal);
+        return pushKV(key, tmpVal, checkForDuplicates);
     }
-    bool pushKV(const std::string& key, int val_) {
+    bool pushKV(const std::string& key, int val_, bool checkForDuplicates = true) {
         UniValue tmpVal((int64_t)val_);
-        return pushKV(key, tmpVal);
+        return pushKV(key, tmpVal, checkForDuplicates);
     }
-    bool pushKV(const std::string& key, double val_) {
+    bool pushKV(const std::string& key, double val_, bool checkForDuplicates = true) {
         UniValue tmpVal(val_);
-        return pushKV(key, tmpVal);
+        return pushKV(key, tmpVal, checkForDuplicates);
     }
     bool pushKVs(const UniValue& obj);
 
diff --git a/src/univalue/lib/univalue.cpp b/src/univalue/lib/univalue.cpp
--- a/src/univalue/lib/univalue.cpp
+++ b/src/univalue/lib/univalue.cpp
@@ -130,13 +130,13 @@
     values.push_back(val_);
 }
 
-bool UniValue::pushKV(const std::string& key, const UniValue& val_)
+bool UniValue::pushKV(const std::string& key, const UniValue& val_, bool checkForDuplicates)
 {
     if (typ != VOBJ)
         return false;
 
     size_t idx;
-    if (findKey(key, idx))
+    if (checkForDuplicates && findKey(key, idx))
         values[idx] = val_;
     else
         __pushKV(key, val_);