diff --git a/app/dns/server/nameserver.go b/app/dns/server/nameserver.go
index 9d654d9e..30538158 100644
--- a/app/dns/server/nameserver.go
+++ b/app/dns/server/nameserver.go
@@ -84,7 +84,7 @@ func (v *UDPNameServer) AssignUnusedID(response chan<- *ARecord) uint16 {
 	}
 
 	for {
-		id = uint16(dice.Roll(65536))
+		id = dice.RandomUint16()
 		if _, found := v.requests[id]; found {
 			continue
 		}
diff --git a/common/dice/dice.go b/common/dice/dice.go
index c737e1cf..8ffc1d28 100644
--- a/common/dice/dice.go
+++ b/common/dice/dice.go
@@ -15,6 +15,11 @@ func Roll(n int) int {
 	return rand.Intn(n)
 }
 
+// RandomUint16 returns a random uint16 value.
+func RandomUint16() uint16 {
+	return uint16(rand.Intn(65536))
+}
+
 func init() {
 	rand.Seed(time.Now().Unix())
 }
diff --git a/transport/internet/headers/srtp/srtp.go b/transport/internet/headers/srtp/srtp.go
index 57969298..cb6c41e3 100644
--- a/transport/internet/headers/srtp/srtp.go
+++ b/transport/internet/headers/srtp/srtp.go
@@ -2,9 +2,9 @@ package srtp
 
 import (
 	"context"
-	"math/rand"
 
 	"v2ray.com/core/common"
+	"v2ray.com/core/common/dice"
 	"v2ray.com/core/common/serial"
 )
 
@@ -27,7 +27,7 @@ func (v *SRTP) Write(b []byte) (int, error) {
 func NewSRTP(ctx context.Context, config interface{}) (interface{}, error) {
 	return &SRTP{
 		header: 0xB5E8,
-		number: uint16(rand.Intn(65536)),
+		number: dice.RandomUint16(),
 	}, nil
 }
 
diff --git a/transport/internet/headers/utp/utp.go b/transport/internet/headers/utp/utp.go
index 6aeb1bae..c1b894fd 100644
--- a/transport/internet/headers/utp/utp.go
+++ b/transport/internet/headers/utp/utp.go
@@ -2,9 +2,9 @@ package utp
 
 import (
 	"context"
-	"math/rand"
 
 	"v2ray.com/core/common"
+	"v2ray.com/core/common/dice"
 	"v2ray.com/core/common/serial"
 )
 
@@ -29,7 +29,7 @@ func NewUTP(ctx context.Context, config interface{}) (interface{}, error) {
 	return &UTP{
 		header:       1,
 		extension:    0,
-		connectionId: uint16(rand.Intn(65536)),
+		connectionId: dice.RandomUint16(),
 	}, nil
 }
 
diff --git a/transport/internet/headers/wechat/wechat.go b/transport/internet/headers/wechat/wechat.go
index a949bad4..2995d359 100644
--- a/transport/internet/headers/wechat/wechat.go
+++ b/transport/internet/headers/wechat/wechat.go
@@ -26,7 +26,7 @@ func (vc *VideoChat) Write(b []byte) (int, error) {
 
 func NewVideoChat(ctx context.Context, config interface{}) (interface{}, error) {
 	return &VideoChat{
-		sn: dice.Roll(65535),
+		sn: int(dice.RandomUint16()),
 	}, nil
 }
 
diff --git a/transport/internet/kcp/dialer.go b/transport/internet/kcp/dialer.go
index d6b81e1f..ad8604c1 100644
--- a/transport/internet/kcp/dialer.go
+++ b/transport/internet/kcp/dialer.go
@@ -20,7 +20,7 @@ import (
 )
 
 var (
-	globalConv = uint32(dice.Roll(65536))
+	globalConv = uint32(dice.RandomUint16())
 	globalPool = internal.NewConnectionPool()
 )
 
diff --git a/v2ray_test.go b/v2ray_test.go
index 2566520d..70011eb1 100644
--- a/v2ray_test.go
+++ b/v2ray_test.go
@@ -20,7 +20,7 @@ import (
 func TestV2RayClose(t *testing.T) {
 	assert := assert.On(t)
 
-	port := v2net.Port(dice.Roll(65535))
+	port := v2net.Port(dice.RandomUint16())
 	config := &Config{
 		Inbound: []*proxyman.InboundHandlerConfig{
 			{