diff --git a/go.mod b/go.mod
index 0a55d68..54cf20f 100644
--- a/go.mod
+++ b/go.mod
@@ -1,4 +1,4 @@
-module github.com/xgadget-lab/nexttrace
+module github.com/sjlleo/nexttrace-core
 
 go 1.20
 
diff --git a/trace/tcp_ipv4.go b/trace/tcp_ipv4.go
index 296b9ff..0c15779 100644
--- a/trace/tcp_ipv4.go
+++ b/trace/tcp_ipv4.go
@@ -10,7 +10,7 @@ import (
 
 	"github.com/google/gopacket"
 	"github.com/google/gopacket/layers"
-	"github.com/xgadget-lab/nexttrace/util"
+	"github.com/sjlleo/nexttrace-core/util"
 	"golang.org/x/net/context"
 	"golang.org/x/net/icmp"
 	"golang.org/x/net/ipv4"
diff --git a/trace/tcp_ipv6.go b/trace/tcp_ipv6.go
index 1e229f9..925b2cb 100644
--- a/trace/tcp_ipv6.go
+++ b/trace/tcp_ipv6.go
@@ -10,7 +10,7 @@ import (
 
 	"github.com/google/gopacket"
 	"github.com/google/gopacket/layers"
-	"github.com/xgadget-lab/nexttrace/util"
+	"github.com/sjlleo/nexttrace-core/util"
 	"golang.org/x/net/context"
 	"golang.org/x/net/icmp"
 	"golang.org/x/net/ipv6"
diff --git a/trace/trace.go b/trace/trace.go
index de96015..6438609 100644
--- a/trace/trace.go
+++ b/trace/trace.go
@@ -42,16 +42,6 @@ type Tracer interface {
 func Traceroute(method Method, config Config) (*Result, error) {
 	var tracer Tracer
 
-	if config.MaxHops == 0 {
-		config.MaxHops = 30
-	}
-	if config.NumMeasurements == 0 {
-		config.NumMeasurements = 3
-	}
-	if config.ParallelRequests == 0 {
-		config.ParallelRequests = config.NumMeasurements * 5
-	}
-
 	switch method {
 	case ICMPTrace:
 		if config.DestIP.To4() != nil {
diff --git a/trace/udp_ipv4.go b/trace/udp_ipv4.go
index eb5f918..0ab508c 100644
--- a/trace/udp_ipv4.go
+++ b/trace/udp_ipv4.go
@@ -8,7 +8,7 @@ import (
 
 	"github.com/google/gopacket"
 	"github.com/google/gopacket/layers"
-	"github.com/xgadget-lab/nexttrace/util"
+	"github.com/sjlleo/nexttrace-core/util"
 	"golang.org/x/net/context"
 	"golang.org/x/net/icmp"
 	"golang.org/x/net/ipv4"