diff --git a/api.json b/api.json
index 23aac9f..2cbb17e 100644
--- a/api.json
+++ b/api.json
@@ -15,7 +15,7 @@
 		"behindReverseProxy": false,
 		"blockRefreshInterval": "120ms",
 		"stateUpdateInterval": "3s",
-		"difficulty": 2000000000,
+		"difficulty": 8589934592,
 		"hashrateExpiration": "3h",
 
 		"healthCheck": true,
diff --git a/proxy/stratum.go b/proxy/stratum.go
index bc7366f..7050cd5 100644
--- a/proxy/stratum.go
+++ b/proxy/stratum.go
@@ -198,11 +198,6 @@ func (cs *Session) handleTCPMessage(s *ProxyServer, req *StratumReq) error {
 			return err
 		}
 
-		if params[1] != "EthereumStratum/1.0.0" {
-			log.Println("Unsupported stratum version from", cs.ip)
-			return cs.sendStratumError(req.Id, "unsupported stratum version")
-		}
-
 		cs.ExtranonceSub = true
 		cs.setStratumMode("EthereumStratum/1.0.0")
 		log.Println("Nicehash subscribe", cs.ip)
diff --git a/util/util.go b/util/util.go
index fd5a11c..1fa154e 100644
--- a/util/util.go
+++ b/util/util.go
@@ -1,6 +1,7 @@
 package util
 
 import (
+	"encoding/hex"
 	"math/big"
 	"regexp"
 	"strconv"
@@ -18,6 +19,14 @@ var pow256 = math.BigPow(2, 256)
 var addressPattern = regexp.MustCompile("^0x[0-9a-fA-F]{40}$")
 var zeroHash = regexp.MustCompile("^0?x?0+$")
 
+var Diff1 = StringToBig("0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF")
+
+func StringToBig(h string) *big.Int {
+	n := new(big.Int)
+	n.SetString(h, 0)
+	return n
+}
+
 func IsValidHexAddress(s string) bool {
 	if IsZeroHash(s) || !addressPattern.MatchString(s) {
 		return false
@@ -35,8 +44,13 @@ func MakeTimestamp() int64 {
 
 func GetTargetHex(diff int64) string {
 	difficulty := big.NewInt(diff)
-	diff1 := new(big.Int).Div(pow256, difficulty)
-	return string(hexutil.Encode(diff1.Bytes()))
+	diff1 := new(big.Int).Div(Diff1, difficulty)
+	targetBytes := diff1.Bytes()
+	if len(targetBytes) < 32 {
+		padding := make([]byte, 32-len(targetBytes))
+		targetBytes = append(padding, targetBytes...)
+	}
+	return "0x" + hex.EncodeToString(targetBytes)
 }
 
 func TargetHexToDiff(targetHex string) *big.Int {