diff --git a/extension.neon b/extension.neon
index f631ec5e..d0cb97c9 100644
--- a/extension.neon
+++ b/extension.neon
@@ -310,5 +310,8 @@ services:
 
 	-
 		class: PHPStan\Symfony\SymfonyContainerResultCacheMetaExtension
+		arguments:
+			tmpDir: %tmpDir%
+			containerXmlPath: %symfony.containerXmlPath%
 		tags:
 			- phpstan.resultCacheMetaExtension
diff --git a/src/Symfony/SymfonyContainerResultCacheMetaExtension.php b/src/Symfony/SymfonyContainerResultCacheMetaExtension.php
index 8e2f8028..88ebbe3c 100644
--- a/src/Symfony/SymfonyContainerResultCacheMetaExtension.php
+++ b/src/Symfony/SymfonyContainerResultCacheMetaExtension.php
@@ -4,9 +4,13 @@
 
 use PHPStan\Analyser\ResultCache\ResultCacheMetaExtension;
 use function array_map;
+use function file_get_contents;
+use function file_put_contents;
 use function hash;
+use function hash_file;
 use function ksort;
 use function sort;
+use function sprintf;
 use function var_export;
 
 final class SymfonyContainerResultCacheMetaExtension implements ResultCacheMetaExtension
@@ -16,10 +20,16 @@ final class SymfonyContainerResultCacheMetaExtension implements ResultCacheMetaE
 
 	private ServiceMap $serviceMap;
 
-	public function __construct(ParameterMap $parameterMap, ServiceMap $serviceMap)
+	private string $tmpDir;
+
+	private ?string $containerXmlPath;
+
+	public function __construct(ParameterMap $parameterMap, ServiceMap $serviceMap, string $tmpDir, ?string $containerXmlPath)
 	{
 		$this->parameterMap = $parameterMap;
 		$this->serviceMap = $serviceMap;
+		$this->tmpDir = $tmpDir;
+		$this->containerXmlPath = $containerXmlPath;
 	}
 
 	public function getKey(): string
@@ -28,6 +38,29 @@ public function getKey(): string
 	}
 
 	public function getHash(): string
+	{
+		if ($this->containerXmlPath !== null) {
+			$xmlHash = hash_file('sha256', $this->containerXmlPath);
+			if ($xmlHash === false) {
+				throw new XmlContainerNotExistsException(sprintf('Container %s does not exist', $this->containerXmlPath));
+			}
+			$hashFile = sprintf('%s/%s-%s.hash', $this->tmpDir, $this->getKey(), $xmlHash);
+			$hash = @file_get_contents($hashFile);
+			if ($hash !== false) {
+				return $hash;
+			}
+		}
+
+		$hash = $this->calculateHash();
+
+		if ($this->containerXmlPath !== null) {
+			file_put_contents($hashFile, $hash);
+		}
+
+		return $hash;
+	}
+
+	public function calculateHash(): string
 	{
 		$services = $parameters = [];
 
diff --git a/tests/Symfony/SymfonyContainerResultCacheMetaExtensionTest.php b/tests/Symfony/SymfonyContainerResultCacheMetaExtensionTest.php
index f5c8503f..79c194d3 100644
--- a/tests/Symfony/SymfonyContainerResultCacheMetaExtensionTest.php
+++ b/tests/Symfony/SymfonyContainerResultCacheMetaExtensionTest.php
@@ -4,6 +4,15 @@
 
 use PHPStan\Testing\PHPStanTestCase;
 use function count;
+use function file_get_contents;
+use function file_put_contents;
+use function glob;
+use function mkdir;
+use function rmdir;
+use function sprintf;
+use function sys_get_temp_dir;
+use function uniqid;
+use function unlink;
 
 /**
  * @phpstan-type ContainerContents array{parameters?: ParameterMap, services?: ServiceMap}
@@ -11,6 +20,61 @@
 final class SymfonyContainerResultCacheMetaExtensionTest extends PHPStanTestCase
 {
 
+	private string $tmpDir;
+
+	protected function setUp(): void
+	{
+		parent::setUp();
+		$this->tmpDir = sys_get_temp_dir() . '/phpstan-symfony-test-' . uniqid('', true);
+		mkdir($this->tmpDir, 0777, true);
+	}
+
+	protected function tearDown(): void
+	{
+		$cacheFiles = glob($this->tmpDir . '/*.hash');
+		if ($cacheFiles !== false) {
+			foreach ($cacheFiles as $file) {
+				unlink($file);
+			}
+		}
+		rmdir($this->tmpDir);
+		parent::tearDown();
+	}
+
+	public function testHashIsCalculatedAndWrittenToCacheFileOnCacheMiss(): void
+	{
+		$containerXmlPath = __DIR__ . '/container.xml';
+
+		$extension = new SymfonyContainerResultCacheMetaExtension(
+			new DefaultParameterMap([]),
+			new DefaultServiceMap([]),
+			$this->tmpDir,
+			$containerXmlPath,
+		);
+
+		$hash = $extension->getHash();
+
+		$cacheFile = sprintf('%s/symfonyDiContainer-c55d6ac45b535d6ecc9402cbb93825c38ec7b11b03f66577d0d3549b3d9ef75f.hash', $this->tmpDir);
+		self::assertFileExists($cacheFile);
+		self::assertSame($hash, file_get_contents($cacheFile));
+	}
+
+	public function testCachedHashIsReturnedOnCacheHit(): void
+	{
+		$containerXmlPath = __DIR__ . '/container.xml';
+		$cacheFile = sprintf('%s/symfonyDiContainer-c55d6ac45b535d6ecc9402cbb93825c38ec7b11b03f66577d0d3549b3d9ef75f.hash', $this->tmpDir);
+		file_put_contents($cacheFile, 'pre-computed-hash');
+
+		$extension = new SymfonyContainerResultCacheMetaExtension(
+			new DefaultParameterMap([]),
+			new DefaultServiceMap([]),
+			$this->tmpDir,
+			$containerXmlPath,
+		);
+
+		self::assertSame('pre-computed-hash', $extension->getHash());
+	}
+
 	/**
 	 * @param list<ContainerContents> $sameHashContents
 	 * @param ContainerContents $invalidatingContent
@@ -30,6 +94,8 @@ public function testContainerHashIsCalculatedCorrectly(
 			$currentHash = (new SymfonyContainerResultCacheMetaExtension(
 				$content['parameters'] ?? new DefaultParameterMap([]),
 				$content['services'] ?? new DefaultServiceMap([]),
+				__DIR__ . '/../../tmp',
+				null,
 			))->getHash();
 
 			if ($hash === null) {
@@ -44,6 +110,8 @@ public function testContainerHashIsCalculatedCorrectly(
 			(new SymfonyContainerResultCacheMetaExtension(
 				$invalidatingContent['parameters'] ?? new DefaultParameterMap([]),
 				$invalidatingContent['services'] ?? new DefaultServiceMap([]),
+				__DIR__ . '/../../tmp',
+				null,
 			))->getHash(),
 		);
 	}