diff --git a/composer.json b/composer.json
index f391fd4f..7c49047c 100644
--- a/composer.json
+++ b/composer.json
@@ -16,7 +16,8 @@
         }
     ],
     "require": {
-        "php": ">=5.5.9"
+        "php": ">=5.5.9",
+        "ext-mbstring": "*"
     },
     "require-dev": {
         "laravel/framework": "~5.1",