diff --git a/composer.json b/composer.json
index 73ef709..23e26be 100644
--- a/composer.json
+++ b/composer.json
@@ -7,7 +7,7 @@
     "license": "MIT",
     "require": {
         "php": ">=5.4.0",
-        "guzzlehttp/guzzle": ">=5.0 <=6.3"
+        "guzzlehttp/guzzle": ">=5.0 <=6.3.3"
     },
     "require-dev": {
         "phpunit/phpunit": "~4.8.36",