diff --git a/lib/irslackd.js b/lib/irslackd.js
index 431d43a..2694bf0 100644
--- a/lib/irslackd.js
+++ b/lib/irslackd.js
@@ -506,6 +506,12 @@ class Irslackd {
   async onSlackReady(ircUser, event) {
     // Send MOTD
     this.ircd.write(ircUser.socket, 'irslackd', '001', [ ircUser.ircNick, 'irslackd' ]);
+    // Send RPL_ISUPPORT
+    this.ircd.write(ircUser.socket, 'irslackd', '005', [
+      ircUser.ircNick,
+      'CHANTYPES=#',
+      ':are supported by this server'
+    ]);
     this.ircd.write(ircUser.socket, 'irslackd', '376', [ ircUser.ircNick, 'End of MOTD' ]);
 
     // set user presence to auto instead of away