diff --git a/phpBB/phpbb/db/doctrine/connection_parameter_factory.php b/phpBB/phpbb/db/doctrine/connection_parameter_factory.php
index 740c4b82b7..90e41061fc 100644
--- a/phpBB/phpbb/db/doctrine/connection_parameter_factory.php
+++ b/phpBB/phpbb/db/doctrine/connection_parameter_factory.php
@@ -149,6 +149,7 @@ class connection_parameter_factory
 		$enrichment_tags = [
 			'pdo_mysql' => [
 				'charset' => 'UTF8',
+				'platform' => new mysql_platform(),
 			],
 			'oci8' => [
 				'charset' => 'UTF8',
diff --git a/phpBB/phpbb/db/doctrine/mysql_platform.php b/phpBB/phpbb/db/doctrine/mysql_platform.php
new file mode 100644
index 0000000000..cd368163dd
--- /dev/null
+++ b/phpBB/phpbb/db/doctrine/mysql_platform.php
@@ -0,0 +1,62 @@
+<?php
+/**
+ *
+ * This file is part of the phpBB Forum Software package.
+ *
+ * @copyright (c) phpBB Limited <https://www.phpbb.com>
+ * @license GNU General Public License, version 2 (GPL-2.0)
+ *
+ * For full copyright and license information, please see
+ * the docs/CREDITS.txt file.
+ *
+ */
+
+namespace phpbb\db\doctrine;
+
+use Doctrine\DBAL\Platforms\AbstractMySQLPlatform;
+use Doctrine\DBAL\Schema\TableDiff;
+
+/**
+ * MySQL specific schema handling.
+ *
+ * While adding auto_increment column to MySQL, it must be indexed.
+ * If it's indexed as primary key, it ahould be declared as NOT NULL
+ * because MySQL primary key columns cannot be NULL.
+ */
+class mysql_platform extends AbstractMySQLPlatform
+{
+	/**
+	 * {@inheritDoc}
+	 */
+	public function getAlterTableSQL(TableDiff $diff)
+	{
+		$sql = parent::getAlterTableSQL($diff);
+		$table = $diff->getOldTable();
+		$columns = $diff->getAddedColumns();
+
+		foreach ($columns as $column)
+		{
+			$column_name = $column->getName();
+			if (!empty($column->getAutoincrement()) && $table)
+			{
+				foreach ($sql as $i => $query)
+				{
+					if (stripos($query, "add $column_name"))
+					{
+						if (!$table->getPrimaryKey())
+						{
+							$sql[$i] = str_replace(' DEFAULT NULL', '', $sql[$i]);
+							$sql[$i] .= ' PRIMARY KEY';
+						}
+						else
+						{
+							$sql[$i] .= ", ADD KEY ($column_name)";
+						}
+					}
+				}
+			}
+		}
+
+		return $sql;
+	}
+}
diff --git a/phpBB/phpbb/db/doctrine/postgresql_platform.php b/phpBB/phpbb/db/doctrine/postgresql_platform.php
index 28f846de03..754ea47a99 100644
--- a/phpBB/phpbb/db/doctrine/postgresql_platform.php
+++ b/phpBB/phpbb/db/doctrine/postgresql_platform.php
@@ -18,6 +18,7 @@ use Doctrine\DBAL\Platforms\PostgreSQL94Platform;
 use Doctrine\DBAL\Schema\Index;
 use Doctrine\DBAL\Schema\Sequence;
 use Doctrine\DBAL\Schema\Table;
+use Doctrine\DBAL\Schema\TableDiff;
 use Doctrine\DBAL\Types\BigIntType;
 use Doctrine\DBAL\Types\IntegerType;
 use Doctrine\DBAL\Types\SmallIntType;