diff --git a/public_html/lists/admin/structure.php b/public_html/lists/admin/structure.php
index d808ea78c..89c5fbf49 100644
--- a/public_html/lists/admin/structure.php
+++ b/public_html/lists/admin/structure.php
@@ -286,7 +286,7 @@
     ),
     'admin' => array(
         'id'              => array('integer not null primary key auto_increment', 'sys:ID'),
-        'loginname'       => array('varchar(25) not null', 'Login Name (max 25 chars)'),
+        'loginname'       => array('varchar(66) not null', 'Login Name (max 66 chars)'),
         'namelc'          => array('varchar(255)', 'sys:Normalised loginname'),
         'email'           => array('varchar(255) not null', 'Email'),
         'created'         => array('datetime', 'sys:Time Created'),
@@ -523,4 +523,4 @@
 
 );
 
-$DBstruct = $DBstructuser + $DBstructphplist; # order of tables is essential for smooth upgrade
\ No newline at end of file
+$DBstruct = $DBstructuser + $DBstructphplist; # order of tables is essential for smooth upgrade
diff --git a/public_html/lists/admin/upgrade.php b/public_html/lists/admin/upgrade.php
index 987b4d4d9..05c950293 100644
--- a/public_html/lists/admin/upgrade.php
+++ b/public_html/lists/admin/upgrade.php
@@ -452,6 +452,11 @@ function output($message)
         Sql_Query(sprintf('update %s set template_text="[CONTENT]"',
             $GLOBALS['tables']['template']));
     }
+        //#increase size 'loginname' for the sso plugin
+
+    if (version_compare($dbversion, '3.6.8','<')) {
+        Sql_Query("alter table {$GLOBALS['tables']['admin']} change column loginname loginname varchar(66) default ''");
+    }
 
     //# longblobs are better at mixing character encoding. We don't know the encoding of anything we may want to store in cache
     //# before converting, it's quickest to clear the cache