diff --git a/app/Models/AssetModel.php b/app/Models/AssetModel.php
index afc496ffc5..52884c0bd3 100755
--- a/app/Models/AssetModel.php
+++ b/app/Models/AssetModel.php
@@ -26,7 +26,7 @@ class AssetModel extends SnipeModel
     // Declare the rules for the model validation
     protected $rules = array(
         'name'          => 'required|min:1|max:255',
-        'model_number'      => 'min:1|max:255',
+        'model_number'      => 'max:255|nullable',
         'category_id'       => 'required|integer|exists:categories,id',
         'manufacturer_id'   => 'required|integer|exists:manufacturers,id',
         'eol'   => 'integer:min:0|max:240|nullable',