diff --git a/composer.json b/composer.json
index 2c1639b..6f1e6ee 100644
--- a/composer.json
+++ b/composer.json
@@ -10,6 +10,9 @@
             "email": "aws-sdk-common-runtime@amazon.com"
         }
     ],
+    "config": {
+        "platform": {"php": "7.4"}
+    },
     "minimum-stability": "alpha",
     "require": {
         "php": ">=5.5"