Make serial nullable

Guessing this is new due to later versions of mysql

database/migrations/2019_02_20_234421_make_serial_nullable.php

@@ -0,0 +1,30 @@
+<?php
+
+use Illuminate\Support\Facades\Schema;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Database\Migrations\Migration;
+
+class MakeSerialNullable extends Migration
+{
+    /**
+     * Run the migrations.
+     *
+     * @return void
+     */
+    public function up()
+    {
+        Schema::table('assets', function (Blueprint $table) {
+            $table->string('serial')->nullable()->default(null)->change();
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     *
+     * @return void
+     */
+    public function down()
+    {
+        //
+    }
+}