diff --git a/.phpstan.neon b/.phpstan.neon
index 4d23eabe..cad20e76 100644
--- a/.phpstan.neon
+++ b/.phpstan.neon
@@ -20,3 +20,10 @@ parameters:
 		-
 			message: '~Call to an undefined method .+::children\(\)\.~'
 			path: "src/Bridges/SymfonyBundle/DependencyInjection/Configuration.php"
+		-
+			message: '~Class BackedEnum not found\.~'
+			path: "src/SqlProcessor.php"
+		-
+			message: '~Access to property \$value on an unknown class BackedEnum\.~'
+			path: "src/SqlProcessor.php"
+
diff --git a/composer.json b/composer.json
index 1e4a3e50..3dba3751 100644
--- a/composer.json
+++ b/composer.json
@@ -42,5 +42,10 @@
 		"branch-alias": {
 			"dev-master": "4.0-dev"
 		}
+	},
+	"config": {
+		"allow-plugins": {
+			"phpstan/extension-installer": true
+		}
 	}
 }
diff --git a/src/SqlProcessor.php b/src/SqlProcessor.php
index 003f210b..e66d6ed2 100644
--- a/src/SqlProcessor.php
+++ b/src/SqlProcessor.php
@@ -148,6 +148,10 @@ function ($matches) use ($args, &$j, $last): string {
 	 */
 	public function processModifier(string $type, $value): string
 	{
+		if ($value instanceof \BackedEnum) {
+			$value = $value->value;
+		}
+
 		switch (gettype($value)) {
 			case 'string':
 				switch ($type) {
diff --git a/tests/cases/unit/SqlProcessorTest.backed_enum.phpt b/tests/cases/unit/SqlProcessorTest.backed_enum.phpt
new file mode 100644
index 00000000..74fdfb7d
--- /dev/null
+++ b/tests/cases/unit/SqlProcessorTest.backed_enum.phpt
@@ -0,0 +1,139 @@
+<?php declare(strict_types = 1);
+
+/**
+ * @testCase
+ * @phpVersion >= 8.1
+ */
+
+namespace NextrasTests\Dbal;
+
+
+use Mockery;
+use Nextras\Dbal\Drivers\IDriver;
+use Nextras\Dbal\Exception\InvalidArgumentException;
+use Nextras\Dbal\Platforms\IPlatform;
+use Nextras\Dbal\SqlProcessor;
+use Tester\Assert;
+
+
+require_once __DIR__ . '/../../bootstrap.php';
+
+
+enum DirectionEnum: string
+{
+	case LEFT = 'left';
+	case RIGHT = 'right';
+}
+
+
+enum BinaryEnum: int
+{
+	case ZERO = 0;
+	case ONE = 1;
+}
+
+
+class SqlProcessorBackedEnumTest extends TestCase
+{
+	/** @var IPlatform|Mockery\MockInterface */
+	private $platform;
+
+	/** @var IDriver|Mockery\MockInterface */
+	private $driver;
+
+	/** @var SqlProcessor */
+	private $parser;
+
+
+	protected function setUp()
+	{
+		parent::setUp();
+		$this->driver = Mockery::mock(IDriver::class);
+		$this->platform = \Mockery::mock(IPlatform::class);
+		$this->parser = new SqlProcessor($this->driver, $this->platform);
+	}
+
+
+	public function testString()
+	{
+		$cases = DirectionEnum::cases();
+		foreach ($cases as $case) {
+			$this->driver->shouldReceive('convertStringToSql')->once()->with($case->value)->andReturn('hit');
+			Assert::same('hit', $this->parser->processModifier('s', $case));
+		}
+
+		$cases = BinaryEnum::cases();
+		foreach ($cases as $case) {
+			Assert::exception(
+				function () use ($case) {
+					$this->parser->processModifier('s', $case);
+				},
+				InvalidArgumentException::class,
+				'Modifier %s expects value to be string, integer given.'
+			);
+		}
+
+	}
+
+
+	public function testStringArray()
+	{
+
+		$cases = DirectionEnum::cases();
+		$this->driver->shouldReceive('convertStringToSql')->times(count($cases))
+			->andReturnArg(0);
+		Assert::same('(left, right)', $this->parser->processModifier('s[]', $cases));
+
+		Assert::exception(
+			function () {
+				$cases = BinaryEnum::cases();
+				$this->parser->processModifier('s[]', $cases);
+			},
+			InvalidArgumentException::class,
+			'Modifier %s expects value to be string, integer given.'
+		);
+
+	}
+
+
+	public function testInt()
+	{
+		$cases = DirectionEnum::cases();
+		foreach ($cases as $case) {
+			Assert::exception(
+				function () use ($case) {
+					$this->parser->processModifier('i', $case);
+				},
+				InvalidArgumentException::class,
+				'Modifier %i expects value to be int, string given.'
+			);
+		}
+
+		$cases = BinaryEnum::cases();
+		foreach ($cases as $case) {
+			Assert::same((string) $case->value, $this->parser->processModifier('i', $case));
+		}
+
+	}
+
+
+	public function testIntArray()
+	{
+		$cases = DirectionEnum::cases();
+		Assert::exception(
+			function () use ($cases) {
+				$this->parser->processModifier('i[]', $cases);
+			},
+			InvalidArgumentException::class,
+			'Modifier %i expects value to be int, string given.'
+		);
+
+		$cases = BinaryEnum::cases();
+		Assert::same('(0, 1)', $this->parser->processModifier('i[]', $cases));
+
+	}
+}
+
+
+$test = new SqlProcessorBackedEnumTest();
+$test->run();