diff --git a/code/form/WidgetAreaEditor.php b/code/form/WidgetAreaEditor.php
index 8c7363b..d5139f7 100644
--- a/code/form/WidgetAreaEditor.php
+++ b/code/form/WidgetAreaEditor.php
@@ -42,17 +42,17 @@ class WidgetAreaEditor extends FormField
         $widgets= new ArrayList();
 
         foreach ($this->widgetClasses as $widgetClass) {
-            $classes = ClassInfo::subclassesFor($widgetClass);
+            $classes = ClassInfo::subclassesFor($widgetClass) ?: array();
 
             if (isset($classes['Widget'])) {
                 unset($classes['Widget']);
             } elseif (isset($classes[0]) && $classes[0] == 'Widget') {
                 unset($classes[0]);
             }
-            
+
             foreach ($classes as $class) {
                 $available = Config::inst()->get($class, 'only_available_in');
-                
+
                 if (!empty($available) && is_array($available)) {
                     if (in_array($this->Name, $available)) {
                         $widgets->push(singleton($class));
@@ -62,7 +62,7 @@ class WidgetAreaEditor extends FormField
                 }
             }
         }
-        
+
         return $widgets;
     }