diff --git a/irc_callback.go b/irc_callback.go
index 259bd61..42d0f8a 100644
--- a/irc_callback.go
+++ b/irc_callback.go
@@ -24,7 +24,7 @@ func (irc *IRCConnection) AddCallback(eventcode string, callback func(*IRCEvent)
 func (irc *IRCConnection) ReplaceCallback(i uint8, eventcode string, callback func(*IRCEvent)) {
 	eventcode = strings.ToUpper(eventcode)
 	if event, ok := irc.events[eventcode]; ok {
-		event[i] = callback;
+		event[i] = callback
 	} else {
 		event = make([]func(*IRCEvent), 1, 20)
 		event[0] = callback
@@ -89,6 +89,11 @@ func (irc *IRCConnection) setupCallbacks() {
 		irc.SendRaw(fmt.Sprintf("NICK %s", irc.nick))
 	})
 
+	irc.AddCallback("433", func(e *IRCEvent) {
+		irc.nick = irc.nick + "_"
+		irc.SendRaw(fmt.Sprintf("NICK %s", irc.nick))
+	})
+
 	irc.AddCallback("PONG", func(e *IRCEvent) {
 		ns, _ := strconv.Atoi64(e.Message)
 		fmt.Printf("Lag: %fs\n", float((time.Nanoseconds()-ns))/1000/1000/1000)