diff --git a/bchain/coins/btc/bitcoinrpc.go b/bchain/coins/btc/bitcoinrpc.go
index a85f24ca..77b57546 100644
--- a/bchain/coins/btc/bitcoinrpc.go
+++ b/bchain/coins/btc/bitcoinrpc.go
@@ -573,6 +573,7 @@ func (b *BitcoinRPC) SendRawTransaction(tx string) (string, error) {
 	return res.Result, nil
 }
 
+// GetMempoolEntry returns mempool data for given transaction
 func (b *BitcoinRPC) GetMempoolEntry(txid string) (*bchain.MempoolEntry, error) {
 	glog.V(1).Info("rpc: getmempoolentry")
 
diff --git a/bchain/coins/zec/zcashrpc.go b/bchain/coins/zec/zcashrpc.go
index 636eb949..c4bad28b 100644
--- a/bchain/coins/zec/zcashrpc.go
+++ b/bchain/coins/zec/zcashrpc.go
@@ -155,3 +155,12 @@ func (z *ZCashRPC) GetBlockHeader(hash string) (*bchain.BlockHeader, error) {
 	}
 	return &res.Result, nil
 }
+// EstimateSmartFee returns fee estimation.
+func (b *ZCashRPC) EstimateSmartFee(blocks int, conservative bool) (float64, error) {
+	return 0, errors.New("EstimateSmartFee: not implemented")
+}
+
+// GetMempoolEntry returns mempool data for given transaction
+func (b *ZCashRPC) GetMempoolEntry(txid string) (*bchain.MempoolEntry, error) {
+	return nil, errors.New("GetMempoolEntry: not implemented")
+}