diff --git a/README.md b/README.md
index aeb87a13..221db768 100644
--- a/README.md
+++ b/README.md
@@ -19,7 +19,7 @@ Build status: [![Build Status](https://travis-ci.org/PHPMailer/PHPMailer.svg)](h
 - SMTP authentication with LOGIN, PLAIN, NTLM, CRAM-MD5 and Google's XOAUTH2 mechanisms over SSL and TLS transports
 - Error messages in 47 languages!
 - DKIM and S/MIME signing support
-- Compatible with PHP 5.4 and later
+- Compatible with PHP 5.5 and later
 - Much more!
 
 ## Why you might need it
diff --git a/src/OAuth.php b/src/OAuth.php
index 9dcac819..010ebd5c 100644
--- a/src/OAuth.php
+++ b/src/OAuth.php
@@ -2,7 +2,7 @@
 
 /**
  * PHPMailer - PHP email creation and transport class.
- * PHP Version 5.4
+ * PHP Version 5.5
  * @package PHPMailer
  * @link https://github.com/PHPMailer/PHPMailer/ The PHPMailer GitHub project
  * @author Marcus Bointon (Synchro/coolbru) <phpmailer@synchromedia.co.uk>
diff --git a/src/POP3.php b/src/POP3.php
index dcfb0526..a91b7118 100644
--- a/src/POP3.php
+++ b/src/POP3.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * PHPMailer - PHP email creation and transport class.
- * PHP Version 5.4
+ * PHP Version 5.5
  * @package PHPMailer
  * @link https://github.com/PHPMailer/PHPMailer/ The PHPMailer GitHub project
  * @author Marcus Bointon (Synchro/coolbru) <phpmailer@synchromedia.co.uk>
diff --git a/src/SMTP.php b/src/SMTP.php
index 7cf98caa..e5cd83d7 100644
--- a/src/SMTP.php
+++ b/src/SMTP.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * PHPMailer - PHP email creation and transport class.
- * PHP Version 5.4
+ * PHP Version 5.5
  * @package PHPMailer
  * @link https://github.com/PHPMailer/PHPMailer/ The PHPMailer GitHub project
  * @author Marcus Bointon (Synchro/coolbru) <phpmailer@synchromedia.co.uk>