diff --git a/src/cl.php b/src/cl.php
index 9e406a4..a0fc0dd 100644
--- a/src/cl.php
+++ b/src/cl.php
@@ -336,7 +336,10 @@ class cl {
   static final function merge2(...$arrays): ?array {
     $merged = null;
     foreach ($arrays as $array) {
-      foreach (self::with($array) as $key => $value) {
+      $array = self::withn($array);
+      if ($array === null) continue;
+      $merged ??= [];
+      foreach ($array as $key => $value) {
         $merged[$key] = $value;
       }
     }