Laravel migration to change an unsignedMediumInteger column

I have a need to create a migration that changes an existing unsignedMediumInteger column to nullable().

I have the following in my migration:

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;
use AppNew\Models\SubscriptionType;

return new class extends Migration
{
    public function up()
    {
        Schema::table('subscription_types', function ($table) {
            $table->unsignedMediumInteger('max_number_of_employees')->nullable()->change();
        });
    }
};

This throws an error as below:

INFO Running migrations.

2023_10_25_103141_make_subscription_types_max_number_of_employees_field_nullable 108ms FAIL

Doctrine\DBAL\Exception

Unknown column type "mediuminteger" requested. Any Doctrine type that you use has to be registered with \Doctrine\DBAL\Types\Type::addType(). You can get a list of all the known types with \Doctrine\DBAL\Types\Type::getTypesMap(). If this error occurs during database introspection then you might have forgotten to register all database types for a Doctrine Type. Use AbstractPlatform#registerDoctrineTypeMapping() or have your custom types implement Type#getMappedDatabaseTypes(). If the type name is empty you might have a problem with the cache or forgot some mapping information.

Any pointers on how to get around this, please?

Try this approach:

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Support\Facades\DB;

return new class extends Migration
{
    /**
     * Run the migrations.
     */
    public function up(): void
    {
        DB::statement("ALTER TABLE <table_name> MODIFY COLUMN <column_name> MEDIUMINT UNSIGNED NULL");
    }

    /**
     * Reverse the migrations.
     */
    public function down(): void
    {
        DB::statement("ALTER TABLE <table_name> MODIFY COLUMN <column_name> MEDIUMINT UNSIGNED NOT NULL");
    }
};