diff --git a/composer.json b/composer.json
index 4a1f6b9f..885ac0b3 100644
--- a/composer.json
+++ b/composer.json
@@ -2,6 +2,7 @@
     "require": {
         "php": ">=5.5",
         "ext-json": "*",
+        "ext-gd": "*",
         "ext-pdo": "*",
         "ext-pdo_mysql": "*",
         "ext-xml": "*",