diff --git a/adapter/outbound/vless.go b/adapter/outbound/vless.go
index ceeb52a51..43b4aa214 100644
--- a/adapter/outbound/vless.go
+++ b/adapter/outbound/vless.go
@@ -373,7 +373,7 @@ func (v *Vless) ListenPacketOnStreamConn(ctx context.Context, c net.Conn, metada
 			}, M.SocksaddrFromNet(metadata.UDPAddr())),
 		), v), nil
 	}
-	return newPacketConn(&vlessPacketConn{Conn: c, rAddr: metadata.UDPAddr()}, v), nil
+	return newPacketConn(N.NewThreadSafePacketConn(&vlessPacketConn{Conn: c, rAddr: metadata.UDPAddr()}), v), nil
 }
 
 // SupportUOT implements C.ProxyAdapter