diff --git a/composer.json b/composer.json
index 6cf39b1..a832e1b 100644
--- a/composer.json
+++ b/composer.json
@@ -15,7 +15,7 @@
   "require": {
     "php": "^7.4 || ^8.0",
     "ext-simplexml": "*",
-    "phpstan/phpstan": "^2.0"
+    "phpstan/phpstan": "^2.1.2"
   },
   "conflict": {
     "symfony/framework-bundle": "<3.0"
diff --git a/extension.neon b/extension.neon
index 0658062..34c7d88 100644
--- a/extension.neon
+++ b/extension.neon
@@ -363,3 +363,8 @@ services:
 	-
 		factory: PHPStan\Type\Symfony\ExtensionGetConfigurationReturnTypeExtension
 		tags: [phpstan.broker.dynamicMethodReturnTypeExtension]
+
+	-
+		class: PHPStan\Symfony\SymfonyContainerResultCacheMetaExtension
+		tags:
+			- phpstan.resultCacheMetaExtension
diff --git a/src/Symfony/SymfonyContainerResultCacheMetaExtension.php b/src/Symfony/SymfonyContainerResultCacheMetaExtension.php
new file mode 100644
index 0000000..8e2f802
--- /dev/null
+++ b/src/Symfony/SymfonyContainerResultCacheMetaExtension.php
@@ -0,0 +1,62 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Symfony;
+
+use PHPStan\Analyser\ResultCache\ResultCacheMetaExtension;
+use function array_map;
+use function hash;
+use function ksort;
+use function sort;
+use function var_export;
+
+final class SymfonyContainerResultCacheMetaExtension implements ResultCacheMetaExtension
+{
+
+	private ParameterMap $parameterMap;
+
+	private ServiceMap $serviceMap;
+
+	public function __construct(ParameterMap $parameterMap, ServiceMap $serviceMap)
+	{
+		$this->parameterMap = $parameterMap;
+		$this->serviceMap = $serviceMap;
+	}
+
+	public function getKey(): string
+	{
+		return 'symfonyDiContainer';
+	}
+
+	public function getHash(): string
+	{
+		$services = $parameters = [];
+
+		foreach ($this->parameterMap->getParameters() as $parameter) {
+			$parameters[$parameter->getKey()] = $parameter->getValue();
+		}
+		ksort($parameters);
+
+		foreach ($this->serviceMap->getServices() as $service) {
+			$serviceTags = array_map(
+				static fn (ServiceTag $tag) => [
+					'name' => $tag->getName(),
+					'attributes' => $tag->getAttributes(),
+				],
+				$service->getTags(),
+			);
+			sort($serviceTags);
+
+			$services[$service->getId()] = [
+				'class' => $service->getClass(),
+				'public' => $service->isPublic() ? 'yes' : 'no',
+				'synthetic' => $service->isSynthetic() ? 'yes' : 'no',
+				'alias' => $service->getAlias(),
+				'tags' => $serviceTags,
+			];
+		}
+		ksort($services);
+
+		return hash('sha256', var_export(['parameters' => $parameters, 'services' => $services], true));
+	}
+
+}
diff --git a/src/Symfony/XmlParameterMapFactory.php b/src/Symfony/XmlParameterMapFactory.php
index b893308..4d3d357 100644
--- a/src/Symfony/XmlParameterMapFactory.php
+++ b/src/Symfony/XmlParameterMapFactory.php
@@ -6,8 +6,10 @@
 use PHPStan\ShouldNotHappenException;
 use SimpleXMLElement;
 use function base64_decode;
+use function count;
 use function file_get_contents;
 use function is_numeric;
+use function ksort;
 use function simplexml_load_string;
 use function sprintf;
 use function strpos;
@@ -40,18 +42,23 @@ public function create(): ParameterMap
 
 		/** @var Parameter[] $parameters */
 		$parameters = [];
-		foreach ($xml->parameters->parameter as $def) {
-			/** @var SimpleXMLElement $attrs */
-			$attrs = $def->attributes();
 
-			$parameter = new Parameter(
-				(string) $attrs->key,
-				$this->getNodeValue($def),
-			);
+		if (count($xml->parameters) > 0) {
+			foreach ($xml->parameters->parameter as $def) {
+				/** @var SimpleXMLElement $attrs */
+				$attrs = $def->attributes();
 
-			$parameters[$parameter->getKey()] = $parameter;
+				$parameter = new Parameter(
+					(string) $attrs->key,
+					$this->getNodeValue($def),
+				);
+
+				$parameters[$parameter->getKey()] = $parameter;
+			}
 		}
 
+		ksort($parameters);
+
 		return new DefaultParameterMap($parameters);
 	}
 
diff --git a/src/Symfony/XmlServiceMapFactory.php b/src/Symfony/XmlServiceMapFactory.php
index 734c22c..ac79cb3 100644
--- a/src/Symfony/XmlServiceMapFactory.php
+++ b/src/Symfony/XmlServiceMapFactory.php
@@ -3,7 +3,9 @@
 namespace PHPStan\Symfony;
 
 use SimpleXMLElement;
+use function count;
 use function file_get_contents;
+use function ksort;
 use function simplexml_load_string;
 use function sprintf;
 use function strpos;
@@ -39,35 +41,38 @@ public function create(): ServiceMap
 		$services = [];
 		/** @var Service[] $aliases */
 		$aliases = [];
-		foreach ($xml->services->service as $def) {
-			/** @var SimpleXMLElement $attrs */
-			$attrs = $def->attributes();
-			if (!isset($attrs->id)) {
-				continue;
-			}
-
-			$serviceTags = [];
-			foreach ($def->tag as $tag) {
-				$tagAttrs = ((array) $tag->attributes())['@attributes'] ?? [];
-				$tagName = $tagAttrs['name'];
-				unset($tagAttrs['name']);
-
-				$serviceTags[] = new ServiceTag($tagName, $tagAttrs);
-			}
-
-			$service = new Service(
-				$this->cleanServiceId((string) $attrs->id),
-				isset($attrs->class) ? (string) $attrs->class : null,
-				isset($attrs->public) && (string) $attrs->public === 'true',
-				isset($attrs->synthetic) && (string) $attrs->synthetic === 'true',
-				isset($attrs->alias) ? $this->cleanServiceId((string) $attrs->alias) : null,
-				$serviceTags,
-			);
 
-			if ($service->getAlias() !== null) {
-				$aliases[] = $service;
-			} else {
-				$services[$service->getId()] = $service;
+		if (count($xml->services) > 0) {
+			foreach ($xml->services->service as $def) {
+				/** @var SimpleXMLElement $attrs */
+				$attrs = $def->attributes();
+				if (!isset($attrs->id)) {
+					continue;
+				}
+
+				$serviceTags = [];
+				foreach ($def->tag as $tag) {
+					$tagAttrs = ((array) $tag->attributes())['@attributes'] ?? [];
+					$tagName = $tagAttrs['name'];
+					unset($tagAttrs['name']);
+
+					$serviceTags[] = new ServiceTag($tagName, $tagAttrs);
+				}
+
+				$service = new Service(
+					$this->cleanServiceId((string) $attrs->id),
+					isset($attrs->class) ? (string) $attrs->class : null,
+					isset($attrs->public) && (string) $attrs->public === 'true',
+					isset($attrs->synthetic) && (string) $attrs->synthetic === 'true',
+					isset($attrs->alias) ? $this->cleanServiceId((string) $attrs->alias) : null,
+					$serviceTags,
+				);
+
+				if ($service->getAlias() !== null) {
+					$aliases[] = $service;
+				} else {
+					$services[$service->getId()] = $service;
+				}
 			}
 		}
 		foreach ($aliases as $service) {
@@ -85,6 +90,8 @@ public function create(): ServiceMap
 			);
 		}
 
+		ksort($services);
+
 		return new DefaultServiceMap($services);
 	}
 
diff --git a/tests/Symfony/SymfonyContainerResultCacheMetaExtensionTest.php b/tests/Symfony/SymfonyContainerResultCacheMetaExtensionTest.php
new file mode 100644
index 0000000..f5c8503
--- /dev/null
+++ b/tests/Symfony/SymfonyContainerResultCacheMetaExtensionTest.php
@@ -0,0 +1,294 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Symfony;
+
+use PHPStan\Testing\PHPStanTestCase;
+use function count;
+
+/**
+ * @phpstan-type ContainerContents array{parameters?: ParameterMap, services?: ServiceMap}
+ */
+final class SymfonyContainerResultCacheMetaExtensionTest extends PHPStanTestCase
+{
+
+	/**
+	 * @param list<ContainerContents> $sameHashContents
+	 * @param ContainerContents $invalidatingContent
+	 *
+	 * @dataProvider provideContainerHashIsCalculatedCorrectlyCases
+	 */
+	public function testContainerHashIsCalculatedCorrectly(
+		array $sameHashContents,
+		array $invalidatingContent
+	): void
+	{
+		$hash = null;
+
+		self::assertGreaterThan(0, count($sameHashContents));
+
+		foreach ($sameHashContents as $content) {
+			$currentHash = (new SymfonyContainerResultCacheMetaExtension(
+				$content['parameters'] ?? new DefaultParameterMap([]),
+				$content['services'] ?? new DefaultServiceMap([]),
+			))->getHash();
+
+			if ($hash === null) {
+				$hash = $currentHash;
+			} else {
+				self::assertSame($hash, $currentHash);
+			}
+		}
+
+		self::assertNotSame(
+			$hash,
+			(new SymfonyContainerResultCacheMetaExtension(
+				$invalidatingContent['parameters'] ?? new DefaultParameterMap([]),
+				$invalidatingContent['services'] ?? new DefaultServiceMap([]),
+			))->getHash(),
+		);
+	}
+
+	/**
+	 * @return iterable<string, array{list<ContainerContents>, ContainerContents}>
+	 */
+	public static function provideContainerHashIsCalculatedCorrectlyCases(): iterable
+	{
+		yield 'service "class" changes' => [
+			[
+				[
+					'services' => new DefaultServiceMap([
+						new Service('Foo', 'Foo', true, false, null),
+						new Service('Bar', 'Bar', true, false, null),
+					]),
+				],
+				// Swapping services order in XML file does not affect the calculated hash
+				[
+					'services' => new DefaultServiceMap([
+						new Service('Bar', 'Bar', true, false, null),
+						new Service('Foo', 'Foo', true, false, null),
+					]),
+				],
+			],
+			[
+				'services' => new DefaultServiceMap([
+					new Service('Foo', 'Foo', true, false, null),
+					new Service('Bar', 'BarAdapter', true, false, null),
+				]),
+			],
+		];
+
+		yield 'service visibility changes' => [
+			[
+				[
+					'services' => new DefaultServiceMap([
+						new Service('Foo', 'Foo', true, false, null),
+					]),
+				],
+			],
+			[
+				'services' => new DefaultServiceMap([
+					new Service('Foo', 'Foo', false, false, null),
+				]),
+			],
+		];
+
+		yield 'service syntheticity changes' => [
+			[
+				[
+					'services' => new DefaultServiceMap([
+						new Service('Foo', 'Foo', true, false, null),
+					]),
+				],
+			],
+			[
+				'services' => new DefaultServiceMap([
+					new Service('Foo', 'Foo', true, true, null),
+				]),
+			],
+		];
+
+		yield 'service alias changes' => [
+			[
+				[
+					'services' => new DefaultServiceMap([
+						new Service('Foo', 'Foo', true, false, null),
+						new Service('Bar', 'Bar', true, false, null),
+						new Service('Baz', null, true, false, 'Foo'),
+					]),
+				],
+				// Swapping services order in XML file does not affect the calculated hash
+				[
+					'services' => new DefaultServiceMap([
+						new Service('Baz', null, true, false, 'Foo'),
+						new Service('Bar', 'Bar', true, false, null),
+						new Service('Foo', 'Foo', true, false, null),
+					]),
+				],
+			],
+			[
+				'services' => new DefaultServiceMap([
+					new Service('Foo', 'Foo', true, false, null),
+					new Service('Bar', 'Bar', true, false, null),
+					new Service('Baz', null, true, false, 'Bar'),
+				]),
+			],
+		];
+
+		yield 'service tag attributes changes' => [
+			[
+				[
+					'services' => new DefaultServiceMap([
+						new Service('Foo', 'Foo', true, false, null, [
+							new ServiceTag('foo.bar', ['baz' => 'bar']),
+							new ServiceTag('foo.baz', ['baz' => 'baz']),
+						]),
+					]),
+				],
+				[
+					'services' => new DefaultServiceMap([
+						new Service('Foo', 'Foo', true, false, null, [
+							new ServiceTag('foo.baz', ['baz' => 'baz']),
+							new ServiceTag('foo.bar', ['baz' => 'bar']),
+						]),
+					]),
+				],
+			],
+			[
+				'services' => new DefaultServiceMap([
+					new Service('Foo', 'Foo', true, false, null, [
+						new ServiceTag('foo.bar', ['baz' => 'bar']),
+						new ServiceTag('foo.baz', ['baz' => 'buzz']),
+					]),
+				]),
+			],
+		];
+
+		yield 'service tag added' => [
+			[
+				[
+					'services' => new DefaultServiceMap([
+						new Service('Foo', 'Foo', true, false, null, [
+							new ServiceTag('foo.bar', ['baz' => 'bar']),
+						]),
+					]),
+				],
+			],
+			[
+				'services' => new DefaultServiceMap([
+					new Service('Foo', 'Foo', true, false, null, [
+						new ServiceTag('foo.bar', ['baz' => 'bar']),
+						new ServiceTag('foo.baz', ['baz' => 'baz']),
+					]),
+				]),
+			],
+		];
+
+		yield 'service tag removed' => [
+			[
+				[
+					'services' => new DefaultServiceMap([
+						new Service('Foo', 'Foo', true, false, null, [
+							new ServiceTag('foo.bar', ['baz' => 'bar']),
+							new ServiceTag('foo.baz', ['baz' => 'baz']),
+						]),
+					]),
+				],
+			],
+			[
+				'services' => new DefaultServiceMap([
+					new Service('Foo', 'Foo', true, false, null, [
+						new ServiceTag('foo.bar', ['baz' => 'bar']),
+					]),
+				]),
+			],
+		];
+
+		yield 'new service added' => [
+			[
+				[
+					'services' => new DefaultServiceMap([
+						new Service('Foo', 'Foo', true, false, null),
+					]),
+				],
+			],
+			[
+				'services' => new DefaultServiceMap([
+					new Service('Foo', 'Foo', true, false, null),
+					new Service('Bar', 'Bar', true, false, null),
+				]),
+			],
+		];
+
+		yield 'service removed' => [
+			[
+				[
+					'services' => new DefaultServiceMap([
+						new Service('Foo', 'Foo', true, false, null),
+						new Service('Bar', 'Bar', true, false, null),
+					]),
+				],
+			],
+			[
+				'services' => new DefaultServiceMap([
+					new Service('Foo', 'Foo', true, false, null),
+				]),
+			],
+		];
+
+		yield 'parameter value changes' => [
+			[
+				[
+					'parameters' => new DefaultParameterMap([
+						new Parameter('foo', 'foo'),
+						new Parameter('bar', 'bar'),
+					]),
+				],
+				[
+					'parameters' => new DefaultParameterMap([
+						new Parameter('bar', 'bar'),
+						new Parameter('foo', 'foo'),
+					]),
+				],
+			],
+			[
+				'parameters' => new DefaultParameterMap([
+					new Parameter('foo', 'foo'),
+					new Parameter('bar', 'buzz'),
+				]),
+			],
+		];
+
+		yield 'new parameter added' => [
+			[
+				[
+					'parameters' => new DefaultParameterMap([
+						new Parameter('foo', 'foo'),
+					]),
+				],
+			],
+			[
+				'parameters' => new DefaultParameterMap([
+					new Parameter('foo', 'foo'),
+					new Parameter('bar', 'bar'),
+				]),
+			],
+		];
+
+		yield 'parameter removed' => [
+			[
+				[
+					'parameters' => new DefaultParameterMap([
+						new Parameter('foo', 'foo'),
+						new Parameter('bar', 'bar'),
+					]),
+				],
+			],
+			[
+				'parameters' => new DefaultParameterMap([
+					new Parameter('foo', 'foo'),
+				]),
+			],
+		];
+	}
+
+}