diff --git a/composer.json b/composer.json
index a3ba080..b841f1e 100644
--- a/composer.json
+++ b/composer.json
@@ -26,7 +26,7 @@
         }
     },
     "require-dev" : {
-        "php": "~7.1",
+        "php": "~7.0",
         "phpunit/phpunit": "~6.0",
         "squizlabs/php_codesniffer": "3.*",
         "php-coveralls/php-coveralls": "2.1.*"