diff --git a/composer.json b/composer.json
index a26edd05c..0f57b3539 100644
--- a/composer.json
+++ b/composer.json
@@ -61,7 +61,10 @@
         ]
     },
     "config": {
-        "preferred-install": "dist"
+        "preferred-install": "dist",
+        "platform": {
+            "php": "7.0"
+        }
     },
     "minimum-stability": "dev",
     "prefer-stable": true,