diff --git a/lib/irc.js b/lib/irc.js
index ee797241..314f374c 100644
--- a/lib/irc.js
+++ b/lib/irc.js
@@ -660,8 +660,8 @@ function Client(server, nick, opt) {
             // for sasl
             case 'CAP':
                 if (message.args[0] === '*' &&
-                     message.args[1] === 'ACK' &&
-                     message.args[2] === 'sasl ') // there's a space after sasl
+                    message.args[1] === 'ACK' &&
+                    message.args[2].split(' ').includes('sasl'))
                     self._send('AUTHENTICATE', self.opt.saslType);
                 break;
             case 'AUTHENTICATE':