diff --git a/go.mod b/go.mod
index e76a488..2846c94 100644
--- a/go.mod
+++ b/go.mod
@@ -2,7 +2,11 @@ module github.com/micro/mdns
 
 require (
 	github.com/miekg/dns v1.1.3
-	golang.org/x/crypto v0.0.0-20190130090550-b01c7a725664 // indirect
 	golang.org/x/net v0.0.0-20190125091013-d26f9f9a57f3
-	golang.org/x/sys v0.0.0-20190129075346-302c3dd5f1cc // indirect
+)
+
+require (
+	golang.org/x/crypto v0.0.0-20190130090550-b01c7a725664 // indirect
+	golang.org/x/sync v0.1.0 // indirect
+	golang.org/x/sys v0.1.0 // indirect
 )
diff --git a/go.sum b/go.sum
index c7e8be9..123eefd 100644
--- a/go.sum
+++ b/go.sum
@@ -4,5 +4,7 @@ golang.org/x/crypto v0.0.0-20190130090550-b01c7a725664 h1:YbZJ76lQ1BqNhVe7dKTSB6
 golang.org/x/crypto v0.0.0-20190130090550-b01c7a725664/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/net v0.0.0-20190125091013-d26f9f9a57f3 h1:ulvT7fqt0yHWzpJwI57MezWnYDVpCAYBVuYst/L+fAY=
 golang.org/x/net v0.0.0-20190125091013-d26f9f9a57f3/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
-golang.org/x/sys v0.0.0-20190129075346-302c3dd5f1cc h1:WiYx1rIFmx8c0mXAFtv5D/mHyKe1+jmuP7PViuwqwuQ=
-golang.org/x/sys v0.0.0-20190129075346-302c3dd5f1cc/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
+golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.1.0 h1:kunALQeHf1/185U1i0GOB/fy1IPRDDpuoOOqRReG57U=
+golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=