diff --git a/mail_imap_ssl.t b/mail_imap_ssl.t
index 4ba3bbe..145ac14 100644
--- a/mail_imap_ssl.t
+++ b/mail_imap_ssl.t
@@ -207,6 +207,7 @@
 );
 $s->ok('trusted cert');
 $s->send('1 AUTHENTICATE PLAIN ' . $cred->("s5"));
+$s->read();
 undef $s;
 
 # test auth_http request header fields with access_log