diff --git a/composer.json b/composer.json
index 1a1d334..a48bcaa 100644
--- a/composer.json
+++ b/composer.json
@@ -25,7 +25,7 @@
         "ext-json": "*",
         "symfony/process": "^6.3",
         "kohanaworld/hmmmath": ">=0.9.0",
-        "guzzlehttp/guzzle": "^7.8",
+        "guzzlehttp/guzzle": "8.0.x-dev",
         "slim/slim": "^4.12",
         "friendsofphp/php-cs-fixer": "^3.16",
         "charescape/serialize-closure": "^3.8",