diff --git a/composer.json b/composer.json
index 477326e..af4f5d0 100644
--- a/composer.json
+++ b/composer.json
@@ -33,8 +33,8 @@
     },
     "require": {
         "php": ">=5.6.4",
-        "guzzlehttp/guzzle": "~6.3",
-        "guzzlehttp/psr7": "^1.4.2",
+        "guzzlehttp/guzzle": "^6.3|^7.0",
+        "guzzlehttp/psr7": "^1.4.2|^2.0",
         "paragonie/random_compat": "~1.4|~2.0",
         "psr/http-message": "^1.0"
     },