diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index 0c38b5f..469f777 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -899,7 +899,9 @@ function drupal_get_filename($type, $name, $filename = NULL) {
   }
   else {
     if ($type == 'module') {
-      $files[$type] = drupal_extension_handler()->getEnabledModules();
+      if (empty($files[$type])) {
+        $files[$type] = drupal_extension_handler()->getEnabledModules();
+      }
       if (isset($files[$type][$name])) {
         return $files[$type][$name];
       }