diff --git a/classes/pref/prefs.php b/classes/pref/prefs.php
index c1351d12d13af50f90cad66662848c1c2b4ccc17..fb1aff3f4ae1c60caa13777815dc7e5664a58641 100644
--- a/classes/pref/prefs.php
+++ b/classes/pref/prefs.php
@@ -660,7 +660,7 @@ class Pref_Prefs extends Handler_Protected {
 					continue;
 				}
 
-				if ($item = $prefs_available[$pref_name]) {
+				if (isset($prefs_available[$pref_name]) &&$item = $prefs_available[$pref_name]) {
 
 					print "<fieldset class='prefs'>";