diff --git a/tests/TestCase.php b/tests/TestCase.php
index c911b753..397c713b 100755
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -116,11 +116,11 @@ class TestCase extends Illuminate\Foundation\Testing\TestCase
      * @param array $data
      * @return array
      */
-    protected function transformData($data)
+    protected function transformData(&$data)
     {
-        foreach($data as $key => $value) {
-            if(is_object($value)) {
-                $value = $this->transformData($value);
+        foreach($data as $key => &$value) {
+            if(is_array($value)) {
+                $this->transformData($value);
             }
 
             if (is_subclass_of($value, App\Interfaces\Unit::class)) {