diff --git a/src/Drivers/Mysqli/MysqliDriver.php b/src/Drivers/Mysqli/MysqliDriver.php
index caff3112..f66fe497 100644
--- a/src/Drivers/Mysqli/MysqliDriver.php
+++ b/src/Drivers/Mysqli/MysqliDriver.php
@@ -226,15 +226,23 @@ public function convertToSql($value, $type)
 
 			case self::TYPE_DATETIME:
 				if ($value->getTimezone()->getName() !== $this->connectionTz->getName()) {
-					$value = clone $value;
-					$value->setTimezone($this->connectionTz);
+					if ($value instanceof \DateTimeImmutable) {
+						$value = $value->setTimezone($this->connectionTz);
+					} else {
+						$value = clone $value;
+						$value->setTimezone($this->connectionTz);
+					}
 				}
 				return "'" . $value->format('Y-m-d H:i:s') . "'";
 
 			case self::TYPE_DATETIME_SIMPLE:
 				if ($value->getTimezone()->getName() !== $this->simpleStorageTz->getName()) {
-					$value = clone $value;
-					$value->setTimeZone($this->simpleStorageTz);
+					if ($value instanceof \DateTimeImmutable) {
+						$value = $value->setTimezone($this->simpleStorageTz);
+					} else {
+						$value = clone $value;
+						$value->setTimeZone($this->simpleStorageTz);
+					}
 				}
 				return "'" . $value->format('Y-m-d H:i:s') . "'";
 
diff --git a/src/Drivers/Pgsql/PgsqlDriver.php b/src/Drivers/Pgsql/PgsqlDriver.php
index 4a48bcc0..22cf8c53 100644
--- a/src/Drivers/Pgsql/PgsqlDriver.php
+++ b/src/Drivers/Pgsql/PgsqlDriver.php
@@ -220,15 +220,23 @@ public function convertToSql($value, $type)
 
 			case self::TYPE_DATETIME:
 				if ($value->getTimezone()->getName() !== $this->connectionTz->getName()) {
-					$value = clone $value;
-					$value->setTimezone($this->connectionTz);
+					if ($value instanceof \DateTimeImmutable) {
+						$value = $value->setTimezone($this->connectionTz);
+					} else {
+						$value = clone $value;
+						$value->setTimezone($this->connectionTz);
+					}
 				}
 				return "'" . $value->format('Y-m-d H:i:s') . "'";
 
 			case self::TYPE_DATETIME_SIMPLE:
 				if ($value->getTimezone()->getName() !== $this->simpleStorageTz->getName()) {
-					$value = clone $value;
-					$value->setTimezone($this->simpleStorageTz);
+					if ($value instanceof \DateTimeImmutable) {
+						$value = $value->setTimezone($this->simpleStorageTz);
+					} else {
+						$value = clone $value;
+						$value->setTimezone($this->simpleStorageTz);
+					}
 				}
 				return "'" . $value->format('Y-m-d H:i:s') . "'";
 
diff --git a/tests/cases/integration/datetime.mysql.phpt b/tests/cases/integration/datetime.mysql.phpt
index fbcb6035..a4d9b85d 100644
--- a/tests/cases/integration/datetime.mysql.phpt
+++ b/tests/cases/integration/datetime.mysql.phpt
@@ -8,7 +8,10 @@
 namespace NextrasTests\Dbal;
 
 use DateTime;
+use DateTimeImmutable;
 use Tester\Assert;
+use Tester\Environment;
+
 
 require_once __DIR__ . '/../../bootstrap.php';
 
@@ -61,6 +64,55 @@ class DateTimeMysqlTest extends IntegrationTestCase
 	}
 
 
+	public function testWriteStorageTZUTCImmutable()
+	{
+		if (PHP_VERSION_ID < 50500) {
+			Environment::skip('DateTimeImmutable tested only in PHP >= 5.5');
+		}
+
+		$connection = $this->createConnection([
+			'simpleStorageTz' => 'UTC',
+			'connectionTz' => 'Europe/Prague',
+		]);
+
+		$connection->query('DROP TABLE IF EXISTS dates_write2');
+		$connection->query('
+			CREATE TABLE dates_write2 (
+				a datetime,
+				b timestamp
+			);
+		');
+
+		$connection->query(
+			'INSERT INTO dates_write2 VALUES (%dts, %dt)',
+			new DateTimeImmutable('2015-01-01 12:00:00'), // 11:00 UTC
+			new DateTimeImmutable('2015-01-01 12:00:00')  // 11:00 UTC
+		);
+
+		$result = $connection->query('SELECT * FROM dates_write2');
+		$result->setValueNormalization(FALSE);
+
+		$row = $result->fetch();
+		Assert::same('2015-01-01 11:00:00', $row->a);
+		Assert::same('2015-01-01 12:00:00', $row->b);
+
+
+		$connection->query('DELETE FROM dates_write2');
+		$connection->query(
+			'INSERT INTO dates_write2 VALUES (%dts, %dt)',
+			new DateTimeImmutable('2015-01-01 12:00:00'),             // 11:00 UTC
+			new DateTimeImmutable('2015-01-01 12:00:00 Europe/Kiev')  // 10:00 UTC
+		);
+
+		$result = $connection->query('SELECT * FROM dates_write2');
+		$result->setValueNormalization(FALSE);
+
+		$row = $result->fetch();
+		Assert::same('2015-01-01 11:00:00', $row->a);
+		Assert::same('2015-01-01 11:00:00', $row->b);
+	}
+
+
 	public function testReadStorageTZUTC()
 	{
 		$connection = $this->createConnection([
diff --git a/tests/cases/integration/datetime.pgsql.phpt b/tests/cases/integration/datetime.pgsql.phpt
index 89895a5d..bdc30779 100644
--- a/tests/cases/integration/datetime.pgsql.phpt
+++ b/tests/cases/integration/datetime.pgsql.phpt
@@ -8,7 +8,10 @@
 namespace NextrasTests\Dbal;
 
 use DateTime;
+use DateTimeImmutable;
 use Tester\Assert;
+use Tester\Environment;
+
 
 require_once __DIR__ . '/../../bootstrap.php';
 
@@ -61,6 +64,55 @@ class DateTimePostgreTest extends IntegrationTestCase
 	}
 
 
+	public function testWriteStorageTZUTCImmutable()
+	{
+		if (PHP_VERSION_ID < 50500) {
+			Environment::skip('DateTimeImmutable tested only in PHP >= 5.5');
+		}
+
+		$connection = $this->createConnection([
+			'simpleStorageTz' => 'UTC',
+			'connectionTz' => 'Europe/Prague',
+		]);
+
+		$connection->query('DROP TABLE IF EXISTS dates_write2');
+		$connection->query('
+			CREATE TABLE dates_write2 (
+				a timestamp,
+				b timestamptz
+			);
+		');
+
+		$connection->query(
+			'INSERT INTO dates_write2 VALUES (%dts, %dt)',
+			new DateTimeImmutable('2015-01-01 12:00:00'), // 11:00 UTC
+			new DateTimeImmutable('2015-01-01 12:00:00')  // 11:00 UTC
+		);
+
+		$result = $connection->query('SELECT * FROM dates_write2');
+		$result->setValueNormalization(FALSE);
+
+		$row = $result->fetch();
+		Assert::same('2015-01-01 11:00:00', $row->a);
+		Assert::same('2015-01-01 12:00:00+01', $row->b);
+
+
+		$connection->query('DELETE FROM dates_write2');
+		$connection->query(
+			'INSERT INTO dates_write2 VALUES (%dts, %dt)',
+			new DateTimeImmutable('2015-01-01 12:00:00'),             // 11:00 UTC
+			new DateTimeImmutable('2015-01-01 12:00:00 Europe/Kiev')  // 10:00 UTC
+		);
+
+		$result = $connection->query('SELECT * FROM dates_write2');
+		$result->setValueNormalization(FALSE);
+
+		$row = $result->fetch();
+		Assert::same('2015-01-01 11:00:00', $row->a);
+		Assert::same('2015-01-01 11:00:00+01', $row->b);
+	}
+
+
 	public function testReadStorageTZUTC()
 	{
 		$connection = $this->createConnection([