diff --git a/core/tests/bootstrap.php b/core/tests/bootstrap.php
index ab54353..c69a52f 100644
--- a/core/tests/bootstrap.php
+++ b/core/tests/bootstrap.php
@@ -18,14 +18,13 @@
  */
 function drupal_phpunit_find_extension_directories($scan_directory) {
   $extensions = array();
-  $dir = new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($scan_directory, \RecursiveDirectoryIterator::FOLLOW_SYMLINKS));
-  foreach ($dir as $d) {
-    if (strpos($d->getPathname(), 'info.yml') !== FALSE) {
+  $dirs = new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($scan_directory, \RecursiveDirectoryIterator::FOLLOW_SYMLINKS));
+  foreach ($dirs as $dir) {
+    if (strpos($dir->getPathname(), 'info.yml') !== FALSE) {
       // Cut off ".info.yml" from the filename for use as the extension name.
-      $extensions[substr($d->getFilename(), 0, -9)] = $d->getPathInfo()->getRealPath();
+      $extensions[substr($dir->getFilename(), 0, -9)] = $dir->getPathInfo()->getRealPath();
     }
   }
-
   return $extensions;
 }