diff --git a/typo3/sysext/core/Classes/Authentication/BackendUserAuthentication.php b/typo3/sysext/core/Classes/Authentication/BackendUserAuthentication.php
index 64f4d265cd8f19b807b0d0d6e4407c4662f07e75..e85d19caa018a4ab04995a5b46d63a3119fb523e 100644
--- a/typo3/sysext/core/Classes/Authentication/BackendUserAuthentication.php
+++ b/typo3/sysext/core/Classes/Authentication/BackendUserAuthentication.php
@@ -249,10 +249,12 @@ class BackendUserAuthentication extends \TYPO3\CMS\Core\Authentication\AbstractU
     public $writeAttemptLog = true;
 
     /**
-     * if > 0 : session-timeout in seconds.
-     * if FALSE/<0 : no timeout.
-     * if string: The string is field name from the user table where the timeout can be found.
-     * @var string|int
+     * Session timeout (on the server)
+     *
+     * If >0: session-timeout in seconds.
+     * If 0: no timeout.
+     *
+     * @var int
      */
     public $sessionTimeout = 6000;
 
diff --git a/typo3/sysext/frontend/Classes/Authentication/FrontendUserAuthentication.php b/typo3/sysext/frontend/Classes/Authentication/FrontendUserAuthentication.php
index 0416a7cf350e507767a7d2e7eb45640751b15f03..42b0b1d7c7a264a54bde0d3880610a1a00c29fd7 100644
--- a/typo3/sysext/frontend/Classes/Authentication/FrontendUserAuthentication.php
+++ b/typo3/sysext/frontend/Classes/Authentication/FrontendUserAuthentication.php
@@ -39,10 +39,12 @@ class FrontendUserAuthentication extends AbstractUserAuthentication
     protected $sessionDataLifetime = 86400;
 
     /**
-     * if > 0 : session-timeout in seconds.
-     * if FALSE/<0 : no timeout.
-     * if string: The string is field name from the user table where the timeout can be found.
-     * @var string|int
+     * Session timeout (on the server)
+     *
+     * If >0: session-timeout in seconds.
+     * If 0: no timeout.
+     *
+     * @var int
      */
     public $sessionTimeout = 6000;