diff --git a/irc.go b/irc.go
index b79fca7..de8f6a5 100644
--- a/irc.go
+++ b/irc.go
@@ -428,17 +428,16 @@ func (irc *Connection) Connect(server string) error {
 	if len(irc.Server) == 0 {
 		return errors.New("empty 'server'")
 	}
-	if strings.Count(irc.Server, ":") != 1 {
-		return errors.New("wrong number of ':' in address")
-	}
 	if strings.Index(irc.Server, ":") == 0 {
 		return errors.New("hostname is missing")
 	}
 	if strings.Index(irc.Server, ":") == len(irc.Server)-1 {
 		return errors.New("port missing")
 	}
-	// check for valid range
-	ports := strings.Split(irc.Server, ":")[1]
+	_, ports, err := net.SplitHostPort(irc.Server)
+	if err != nil {
+		return errors.New("wrong address string")
+	}
 	port, err := strconv.Atoi(ports)
 	if err != nil {
 		return errors.New("extracting port failed")