diff --git a/src/composer.json b/src/composer.json
index c76b6ea..b221b99 100644
--- a/src/composer.json
+++ b/src/composer.json
@@ -1,9 +1,10 @@
 {
     "require": {
+        "aws/aws-sdk-php": "^3.192",
         "guzzlehttp/guzzle": "~6.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^7",
+        "phpunit/phpunit": "^6.5.14",
         "mockery/mockery": "^1.2"
     },
     "autoload": {