diff --git a/composer.json b/composer.json
index 885ac0b3..5419b7bc 100644
--- a/composer.json
+++ b/composer.json
@@ -1,6 +1,7 @@
 {
     "require": {
         "php": ">=5.5",
+        "ext-dom": "*",
         "ext-json": "*",
         "ext-gd": "*",
         "ext-pdo": "*",