diff --git a/lib/private/DB/ConnectionFactory.php b/lib/private/DB/ConnectionFactory.php
index 91ed009f4d45d..8182a07d91327 100644
--- a/lib/private/DB/ConnectionFactory.php
+++ b/lib/private/DB/ConnectionFactory.php
@@ -210,7 +210,7 @@ public function createConnectionParams(string $configPrefix = '', array $additio
 		//additional driver options, eg. for mysql ssl
 		$driverOptions = $this->config->getValue($configPrefix . 'dbdriveroptions', $this->config->getValue('dbdriveroptions', null));
 		if ($driverOptions) {
-			$connectionParams['driverOptions'] = array_merge($connectionParams['driverOptions'], $driverOptions);
+			$connectionParams['driverOptions'] = $driverOptions + ($connectionParams['driverOptions'] ?? []);
 		}
 
 		// set default table creation options
diff --git a/tests/lib/DB/ConnectionFactoryTest.php b/tests/lib/DB/ConnectionFactoryTest.php
index 5e57bb6be139b..42f363fbff859 100644
--- a/tests/lib/DB/ConnectionFactoryTest.php
+++ b/tests/lib/DB/ConnectionFactoryTest.php
@@ -41,6 +41,53 @@ public function testSplitHostFromPortAndSocket($host, array $expected): void {
 		$this->assertEquals($expected, self::invokePrivate($factory, 'splitHostFromPortAndSocket', [$host]));
 	}
 
+	/**
+	 * The numeric value of a PDO MySQL attribute, e.g. `SSL_CA`.
+	 *
+	 * The values are not stable across PHP versions, so they must never be hardcoded.
+	 * Since PHP 8.5 the `PDO::MYSQL_ATTR_*` constants are deprecated in favor of
+	 * `Pdo\Mysql::ATTR_*`, and either only exists with the MySQL driver installed.
+	 */
+	private function mysqlAttribute(string $name): int {
+		if (!extension_loaded('pdo_mysql')) {
+			$this->markTestSkipped('The pdo_mysql extension is required to resolve the PDO attribute values');
+		}
+		if (PHP_VERSION_ID >= 80500 && class_exists(\Pdo\Mysql::class)) {
+			return (int)constant('Pdo\Mysql::ATTR_' . $name);
+		}
+		return (int)constant('PDO::MYSQL_ATTR_' . $name);
+	}
+
+	public function testMysqlSslConnection(): void {
+		/** @var SystemConfig|\PHPUnit\Framework\MockObject\MockObject $config */
+		$config = $this->createMock(SystemConfig::class);
+		$config->method('getValue')
+			->willReturnCallback(function ($key, $default) {
+				return match ($key) {
+					'dbdriveroptions' => [
+						$this->mysqlAttribute('SSL_CA') => 'rootCA.crt',
+						$this->mysqlAttribute('SSL_CERT') => 'client.crt',
+						$this->mysqlAttribute('SSL_KEY')  => 'client.key',
+						$this->mysqlAttribute('SSL_VERIFY_SERVER_CERT') => true,
+					],
+					'dbtype' => 'mysql',
+					default => $default,
+				};
+			});
+		$factory = new ConnectionFactory($config);
+
+		$params = $factory->createConnectionParams();
+
+		$this->assertEquals('pdo_mysql', $params['driver']);
+		$this->assertEquals([
+			$this->mysqlAttribute('FOUND_ROWS') => true,
+			$this->mysqlAttribute('SSL_CA') => 'rootCA.crt',
+			$this->mysqlAttribute('SSL_CERT') => 'client.crt',
+			$this->mysqlAttribute('SSL_KEY') => 'client.key',
+			$this->mysqlAttribute('SSL_VERIFY_SERVER_CERT') => true,
+		], $params['driverOptions']);
+	}
+
 	public function testPgsqlSslConnection(): void {
 		/** @var SystemConfig|\PHPUnit\Framework\MockObject\MockObject $config */
 		$config = $this->createMock(SystemConfig::class);
@@ -48,6 +95,10 @@ public function testPgsqlSslConnection(): void {
 			->willReturnCallback(function ($key, $default) {
 				return match ($key) {
 					'dbtype' => 'pgsql',
+					'dbdriveroptions' => [
+						1 => 'foo',
+						3 => 'bar',
+					],
 					'pgsql_ssl' => [
 						'mode' => 'verify-full',
 						'cert' => 'client.crt',
@@ -68,5 +119,9 @@ public function testPgsqlSslConnection(): void {
 		$this->assertEquals('client.crt', $params['sslcert']);
 		$this->assertEquals('client.key', $params['sslkey']);
 		$this->assertEquals('client.crl', $params['sslcrl']);
+		$this->assertEquals([
+			1 => 'foo',
+			3 => 'bar',
+		], $params['driverOptions']);
 	}
 }