diff --git a/composer.json b/composer.json
index bb3ed19e..00bd0926 100644
--- a/composer.json
+++ b/composer.json
@@ -7,7 +7,8 @@
     "require": {
         "php": ">=5.6 <=7.4.14",
         "ext-intl": "*",
-        "zendframework/zendframework": "^2.5.3"
+        "zendframework/zendframework": "^2.5.3",
+        "symfony/polyfill-php71": "^1.19"
     },
 
     "autoload": {