diff --git entity.module entity.module
index c4df05f..10d08c0 100644
--- entity.module
+++ entity.module
@@ -755,7 +755,7 @@ function entity_ui_controller($type = NULL) {
   if (isset($type) && !isset($static[$type])) {
     $info = entity_get_info($type);
     $class = isset($info['admin ui']['controller class']) ? $info['admin ui']['controller class'] : 'EntityDefaultUIController';
-    $static[$type] = (isset($info['admin ui']['path']) && $class) ? new $class($type, $info) : FALSE;
+    $static[$type] = (isset($info['admin ui']['path']) && $class && class_exists($class)) ? new $class($type, $info) : FALSE;
   }
   if (!isset($type) && !isset($all)) {
     // Invoke the function for each type to ensure we have fully populated the