diff --git a/installer/rcube_install.php b/installer/rcube_install.php
index 12cd5c10d..c4704a3a8 100644
--- a/installer/rcube_install.php
+++ b/installer/rcube_install.php
@@ -102,7 +102,7 @@ class rcube_install
   {
     $value = $this->is_post && (isset($_POST["_$name"]) || $this->config_props[$name]) ? $_POST["_$name"] : $this->config[$name];
     
-    if ($name == 'des_key' && !isset($_REQUEST["_$name"]))
+    if ($name == 'des_key' && !$this->configured && !isset($_REQUEST["_$name"]))
       $value = rcube_install::random_key(24);
     
     return $value !== null && $value !== '' ? $value : $default;
@@ -147,6 +147,9 @@ class rcube_install
         if (count($value) <= 1)
           $value = $value[0];
       }
+      else if ($prop == 'pagesize') {
+        $value = max(2, intval($value));
+      }
       else if ($prop == 'smtp_user' && !empty($_POST['_smtp_user_u'])) {
         $value = '%u';
       }
diff --git a/program/steps/settings/save_prefs.inc b/program/steps/settings/save_prefs.inc
index 8dae7bc47..9ee30a616 100644
--- a/program/steps/settings/save_prefs.inc
+++ b/program/steps/settings/save_prefs.inc
@@ -22,7 +22,7 @@
 $a_user_prefs = array(
   'timezone'     => isset($_POST['_timezone']) ? floatval($_POST['_timezone']) : $CONFIG['timezone'],
   'dst_active'   => isset($_POST['_dst_active']) ? TRUE : FALSE,
-  'pagesize'     => is_numeric($_POST['_pagesize']) ? intval($_POST['_pagesize']) : $CONFIG['pagesize'],
+  'pagesize'     => is_numeric($_POST['_pagesize']) ? max(2, intval($_POST['_pagesize'])) : $CONFIG['pagesize'],
   'prettydate'   => isset($_POST['_pretty_date']) ? TRUE : FALSE,
   'prefer_html'  => isset($_POST['_prefer_html']) ? TRUE : FALSE,
   'htmleditor'   => isset($_POST['_htmleditor']) ? TRUE : FALSE,