diff --git a/core/lib/Drupal/Component/DependencyInjection/Dumper/PhpArrayDumper.php b/core/lib/Drupal/Component/DependencyInjection/Dumper/PhpArrayDumper.php
index a6fa2b9b09..08451b1139 100644
--- a/core/lib/Drupal/Component/DependencyInjection/Dumper/PhpArrayDumper.php
+++ b/core/lib/Drupal/Component/DependencyInjection/Dumper/PhpArrayDumper.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Component\DependencyInjection\Dumper;
 
+use Symfony\Component\DependencyInjection\Argument\IteratorArgument;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
@@ -33,6 +34,9 @@ protected function dumpCollection($collection, &$resolve = FALSE) {
     $code = [];
 
     foreach ($collection as $key => $value) {
+      if ($value instanceof IteratorArgument) {
+        $value = $value->getValues();
+      }
       if (is_array($value)) {
         $code[$key] = $this->dumpCollection($value);
       }