diff --git a/lib/dispatcher/client.js b/lib/dispatcher/client.js
index 87714d5009d..240a494ae51 100644
--- a/lib/dispatcher/client.js
+++ b/lib/dispatcher/client.js
@@ -374,7 +374,7 @@ async function connect (client) {
     assert(idx !== -1)
     const ip = hostname.substring(1, idx)
 
-    assert(net.isIP(ip))
+    assert(net.isIPv6(ip))
     hostname = ip
   }