diff --git a/src/Libs/Model.php b/src/Libs/Model.php
index e58d628..f31d0f6 100644
--- a/src/Libs/Model.php
+++ b/src/Libs/Model.php
@@ -985,19 +985,12 @@ class Model
      *
      * @return void
      */
-    public function setNull(...$attributes): void
+    public function setNull(string ...$attributes): void
     {
-        if (is_array($attributes)) {
-            foreach ($attributes as $att) {
-                if (!in_array($att, $this->toNull)) {
-                    $this->toNull[] = $att;
-                }
+        foreach ($attributes as $att) {
+            if (!in_array($att, $this->toNull)) {
+                $this->toNull[] = $att;
             }
-            return;
-        }
-
-        if (!in_array($attributes, $this->toNull)) {
-            $this->toNull[] = $attributes;
         }
     }
 }