diff --git a/composer.json b/composer.json
index 3acfd893..adc65e16 100644
--- a/composer.json
+++ b/composer.json
@@ -21,6 +21,7 @@
     }
   },
   "require": {
+    "php": "^7.0",
     "guzzlehttp/guzzle": "~6.0|~7.0",
     "illuminate/support": "~5.1|~5.2|~5.3|~5.4|~5.5|~5.6|~5.7|~5.8",
     "nesbot/carbon": "~1.0|~2.0"