client.go | 2 ++

diff --git a/client.go b/client.go
index f88766ea8c1a9f476982cabed0ee1c35f855c1ab..4ccdc1f98dada77739b2bd0ed1116caf935ae8d1 100644
--- a/client.go
+++ b/client.go
@@ -1231,6 +1231,8 @@ 	return ipPort{cl.publicIp(peer), uint16(cl.incomingPeerPort())}
 }
 
 func (cl *Client) ListenAddrs() (ret []net.Addr) {
+	cl.mu.Lock()
+	defer cl.mu.Unlock()
 	cl.eachListener(func(l socket) bool {
 		ret = append(ret, l.Addr())
 		return true