diff --git a/composer.json b/composer.json
index 12c95f0..6f021af 100644
--- a/composer.json
+++ b/composer.json
@@ -26,7 +26,7 @@
   , "require": {
         "php": ">=5.3.9"
       , "react/socket": "0.3.*"
-      , "guzzle/http": ">=3.6.0,<3.8.0-dev"
+      , "guzzle/http": ">=3.6.0,<3.9.0-dev"
       , "symfony/http-foundation": "~2.2"
       , "symfony/routing": "~2.2"
     }