diff --git a/src/Command/BisectCommand.php b/src/Command/BisectCommand.php
index 8cb0c0382d..6e49099a76 100644
--- a/src/Command/BisectCommand.php
+++ b/src/Command/BisectCommand.php
@@ -9,6 +9,7 @@
 use Override;
 use PHPStan\Command\Bisect\BinarySearch;
 use PHPStan\File\FileReader;
+use PHPStan\Internal\HttpClientFactory;
 use Symfony\Component\Console\Command\Command;
 use Symfony\Component\Console\Helper\ProgressBar;
 use Symfony\Component\Console\Input\InputArgument;
@@ -106,7 +107,7 @@ protected function execute(InputInterface $input, OutputInterface $output): int
 			return 1;
 		}
 
-		$client = new Client([
+		$client = HttpClientFactory::createClient([
 			RequestOptions::TIMEOUT => 30,
 			RequestOptions::CONNECT_TIMEOUT => 10,
 			'headers' => [
diff --git a/src/Command/FixerApplication.php b/src/Command/FixerApplication.php
index 8d6432258c..e08d752623 100644
--- a/src/Command/FixerApplication.php
+++ b/src/Command/FixerApplication.php
@@ -7,7 +7,6 @@
 use DateTime;
 use DateTimeImmutable;
 use DateTimeZone;
-use GuzzleHttp\Client;
 use GuzzleHttp\Exception\GuzzleException;
 use GuzzleHttp\RequestOptions;
 use Nette\Utils\Json;
@@ -23,6 +22,7 @@
 use PHPStan\Internal\ComposerHelper;
 use PHPStan\Internal\DirectoryCreator;
 use PHPStan\Internal\DirectoryCreatorException;
+use PHPStan\Internal\HttpClientFactory;
 use PHPStan\PhpDoc\StubFilesProvider;
 use PHPStan\Process\ProcessCanceledException;
 use PHPStan\Process\ProcessCrashedException;
@@ -325,7 +325,7 @@ private function downloadPhar(
 			$output->writeln('<fg=green>Checking if there\'s a new PHPStan Pro release...</>');
 		}
 
-		$client = new Client([
+		$client = HttpClientFactory::createClient([
 			RequestOptions::TIMEOUT => 30,
 			RequestOptions::CONNECT_TIMEOUT => 5,
 		]);
diff --git a/src/Internal/HttpClientFactory.php b/src/Internal/HttpClientFactory.php
new file mode 100644
index 0000000000..cf548fb7fe
--- /dev/null
+++ b/src/Internal/HttpClientFactory.php
@@ -0,0 +1,28 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Internal;
+
+use GuzzleHttp\Client;
+use function extension_loaded;
+
+final class HttpClientFactory
+{
+
+	/**
+	 * @param array<mixed> $config
+	 *
+	 * @see \GuzzleHttp\RequestOptions
+	 */
+	public static function createClient(array $config): Client
+	{
+		if (
+			!isset($config['headers']['Accept-Encoding'])
+			&& extension_loaded('zlib')
+		) {
+			$config['headers']['Accept-Encoding'] = 'gzip,deflate';
+		}
+
+		return new Client($config);
+	}
+
+}