Doctrine default value CURRENT_TIMESTAMP for a column

Question

I am trying to create an entity with created_at field that has default value CURRENT_TIMESTAMP.

But when I try to persist an entity to a database I get this error:

An exception occurred while executing a query: SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'created_at' cannot be null

It looks like doctrine tries to send NULL value explicitly for that column instead of not sending it.

Is it possible to have default value CURRENT_TIMESTAMP for a field that generated on the DBMS side, not by any hooks of the entity or lifecycle callbacks?

Here is my xml mapping:

<?xml version="1.0" encoding="utf-8"?>
<doctrine-mapping xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://doctrine-project.org/schemas/orm/doctrine-mapping https://www.doctrine-project.org/schemas/orm/doctrine-mapping.xsd">
  <entity name="App\Entity\BusinessTrip" table="business_trip">
    <id name="id" type="binary" column="id">
      <generator strategy="IDENTITY"/>
    </id>
    <field name="createdAt" type="datetime" column="created_at" nullable="false">
      <options>
        <option name="default">CURRENT_TIMESTAMP</option>
      </options>
    </field>
    <field name="modifiedAt" type="datetime" column="modified_at" nullable="true"/>
    <field name="deletedAt" type="datetime" column="deleted_at" nullable="true"/>
    <field name="createdBy" type="binary" column="created_by" nullable="false"/>
    <field name="dateFrom" type="date" column="date_from" nullable="false"/>
    <field name="dateTo" type="date" column="date_to" nullable="false"/>
  </entity>
</doctrine-mapping>

Code of the entity is pretty long, so I put only declaration of the field here:

class BusinessTrip implements JsonSerializable
{
    private ?DateTimeInterface $createdAt;

At the point of persisting this entity that field is NULL.