diff --git a/composer.json b/composer.json
index fc8ab83..5df6080 100644
--- a/composer.json
+++ b/composer.json
@@ -49,7 +49,7 @@
         "php-standard-library/psalm-plugin": "^2.3",
         "php-soap/engine-integration-tests": "^1.12",
         "php-soap/psr18-transport": "^2.0",
-        "guzzlehttp/guzzle": "^7.8",
+        "guzzlehttp/guzzle": "^7.8 || ^8.0",
         "phpbench/phpbench": "^1.6"
     },
     "config": {