diff --git a/config/config.inc.php b/config/config.inc.php
index d9f5c0a..a307ec5 100644
--- a/config/config.inc.php
+++ b/config/config.inc.php
@@ -30,6 +30,8 @@ $config['log_driver'] = 'syslog';
 // %s - domain name after the '@' from e-mail address provided at login screen
 // For example %n = mail.domain.tld, %t = domain.tld
 $config['default_host'] = 'tls://%n';
+$config['imap_auth_type'] = 'PLAIN';
+$config['smtp_auth_type'] = 'PLAIN';
 
 // provide an URL where a user can get support for this Roundcube installation
 // PLEASE DO NOT LINK TO THE ROUNDCUBE.NET WEBSITE HERE!