diff --git a/bchain/coins/blockchain.go b/bchain/coins/blockchain.go
index c90332ae..7e068e67 100644
--- a/bchain/coins/blockchain.go
+++ b/bchain/coins/blockchain.go
@@ -149,10 +149,6 @@ func (c *blockChainWithMetrics) GetMempoolTransactions(address string) (v []stri
 	return c.b.GetMempoolTransactions(address)
 }
 
-func (c *blockChainWithMetrics) GetMempoolSpentOutput(outputTxid string, vout uint32) (v string) {
-	return c.b.GetMempoolSpentOutput(outputTxid, vout)
-}
-
 func (c *blockChainWithMetrics) GetMempoolEntry(txid string) (v *bchain.MempoolEntry, err error) {
 	defer func(s time.Time) { c.observeRPCLatency("GetMempoolEntry", s, err) }(time.Now())
 	return c.b.GetMempoolEntry(txid)
diff --git a/bchain/coins/btc/bitcoinrpc.go b/bchain/coins/btc/bitcoinrpc.go
index cb894517..686efcf2 100644
--- a/bchain/coins/btc/bitcoinrpc.go
+++ b/bchain/coins/btc/bitcoinrpc.go
@@ -575,11 +575,6 @@ func (b *BitcoinRPC) GetMempoolTransactions(address string) ([]string, error) {
 	return b.Mempool.GetTransactions(address)
 }
 
-// GetMempoolSpentOutput returns transaction in mempool which spends given outpoint
-func (b *BitcoinRPC) GetMempoolSpentOutput(outputTxid string, vout uint32) string {
-	return b.Mempool.GetSpentOutput(outputTxid, vout)
-}
-
 // EstimateSmartFee returns fee estimation.
 func (b *BitcoinRPC) EstimateSmartFee(blocks int, conservative bool) (float64, error) {
 	glog.V(1).Info("rpc: estimatesmartfee ", blocks)
diff --git a/bchain/coins/eth/ethrpc.go b/bchain/coins/eth/ethrpc.go
index 26c844bc..9193a9d8 100644
--- a/bchain/coins/eth/ethrpc.go
+++ b/bchain/coins/eth/ethrpc.go
@@ -486,10 +486,6 @@ func (b *EthereumRPC) GetMempoolTransactions(address string) ([]string, error) {
 	return b.Mempool.GetTransactions(address)
 }
 
-func (b *EthereumRPC) GetMempoolSpentOutput(outputTxid string, vout uint32) string {
-	return ""
-}
-
 func (b *EthereumRPC) GetMempoolEntry(txid string) (*bchain.MempoolEntry, error) {
 	return nil, errors.New("GetMempoolEntry: not implemented")
 }
diff --git a/bchain/mempool_nonutxo.go b/bchain/mempool_nonutxo.go
index d30149f6..7a18ca4a 100644
--- a/bchain/mempool_nonutxo.go
+++ b/bchain/mempool_nonutxo.go
@@ -22,13 +22,13 @@ func NewNonUTXOMempool(chain BlockChain) *NonUTXOMempool {
 
 // GetTransactions returns slice of mempool transactions for given address
 func (m *NonUTXOMempool) GetTransactions(address string) ([]string, error) {
-	m.mux.Lock()
-	defer m.mux.Unlock()
 	parser := m.chain.GetChainParser()
 	addrID, err := parser.GetAddrIDFromAddress(address)
 	if err != nil {
 		return nil, err
 	}
+	m.mux.Lock()
+	defer m.mux.Unlock()
 	outpoints := m.addrIDToTx[string(addrID)]
 	txs := make([]string, 0, len(outpoints))
 	for _, o := range outpoints {
diff --git a/bchain/mempool_utxo.go b/bchain/mempool_utxo.go
index fbd73724..d653e0a9 100644
--- a/bchain/mempool_utxo.go
+++ b/bchain/mempool_utxo.go
@@ -7,7 +7,7 @@ import (
 	"github.com/golang/glog"
 )
 
-// addrIndex and outpoint are used also in nonutxo mempool
+// addrIndex and outpoint are used also in non utxo mempool
 type addrIndex struct {
 	addrID string
 	n      int32
@@ -39,13 +39,13 @@ func NewUTXOMempool(chain BlockChain) *UTXOMempool {
 
 // GetTransactions returns slice of mempool transactions for given address
 func (m *UTXOMempool) GetTransactions(address string) ([]string, error) {
-	m.mux.Lock()
-	defer m.mux.Unlock()
 	parser := m.chain.GetChainParser()
 	addrID, err := parser.GetAddrIDFromAddress(address)
 	if err != nil {
 		return nil, err
 	}
+	m.mux.Lock()
+	defer m.mux.Unlock()
 	outpoints := m.addrIDToTx[string(addrID)]
 	txs := make([]string, 0, len(outpoints)+len(outpoints)/2)
 	for _, o := range outpoints {
diff --git a/bchain/types.go b/bchain/types.go
index 73b2b56b..c5a88630 100644
--- a/bchain/types.go
+++ b/bchain/types.go
@@ -141,7 +141,6 @@ type BlockChain interface {
 	// mempool
 	ResyncMempool(onNewTxAddr func(txid string, addr string)) error
 	GetMempoolTransactions(address string) ([]string, error)
-	GetMempoolSpentOutput(outputTxid string, vout uint32) string
 	GetMempoolEntry(txid string) (*MempoolEntry, error)
 	// parser
 	GetChainParser() BlockChainParser
diff --git a/server/https.go b/server/https.go
index cf073e9e..62232f68 100644
--- a/server/https.go
+++ b/server/https.go
@@ -196,12 +196,6 @@ func (s *HTTPServer) transactions(w http.ResponseWriter, r *http.Request) {
 	txList := transactionList{}
 	err = s.db.GetTransactions(address, lower, higher, func(txid string, vout uint32, isOutput bool) error {
 		txList.Txid = append(txList.Txid, txid)
-		if isOutput {
-			input := s.chain.GetMempoolSpentOutput(txid, vout)
-			if input != "" {
-				txList.Txid = append(txList.Txid, txid)
-			}
-		}
 		return nil
 	})
 	if err != nil {
diff --git a/server/socketio.go b/server/socketio.go
index 98465a2f..a654122c 100644
--- a/server/socketio.go
+++ b/server/socketio.go
@@ -127,7 +127,6 @@ func (s *SocketIoServer) txRedirect(w http.ResponseWriter, r *http.Request) {
 type addrOpts struct {
 	Start            int   `json:"start"`
 	End              int   `json:"end"`
-	QueryMempol      bool  `json:"queryMempol"`
 	QueryMempoolOnly bool  `json:"queryMempoolOnly"`
 	From             int   `json:"from"`
 	To               int   `json:"to"`
@@ -276,27 +275,17 @@ func (s *SocketIoServer) getAddressTxids(addr []string, opts *addrOpts) (res res
 		if !opts.QueryMempoolOnly {
 			err = s.db.GetTransactions(address, lower, higher, func(txid string, vout uint32, isOutput bool) error {
 				txids = append(txids, txid)
-				if isOutput && opts.QueryMempol {
-					input := s.chain.GetMempoolSpentOutput(txid, vout)
-					if input != "" {
-						txids = append(txids, txid)
-					}
-				}
 				return nil
 			})
 			if err != nil {
 				return res, err
 			}
-		}
-		if opts.QueryMempoolOnly || opts.QueryMempol {
-			mtxids, err := s.chain.GetMempoolTransactions(address)
+		} else {
+			m, err := s.chain.GetMempoolTransactions(address)
 			if err != nil {
 				return res, err
 			}
-			txids = append(txids, mtxids...)
-		}
-		if err != nil {
-			return res, err
+			txids = append(txids, m...)
 		}
 	}
 	res.Result = uniqueTxidsInReverse(txids)