diff --git a/composer.json b/composer.json
index 1fbde2fe0a4dc0438170f9e282ade46db7e119a3..b2fa7e38b42bf1466a3468455ca876f06c8c78ee 100644
--- a/composer.json
+++ b/composer.json
@@ -12,13 +12,13 @@
     ],
     "require": {
         "php": ">=5.6",
-        "symfony/serializer": "~2.7|~3.0",
+        "symfony/serializer": "~2.7|~3.0|~4.0",
         "paragonie/random_compat": "^1.0|^2.0"
     },
     "require-dev": {
         "phpunit/phpunit": "~5.6",
         "squizlabs/php_codesniffer": "~2.0",
-        "satooshi/php-coveralls": "~1.0",
+        "satooshi/php-coveralls": "~1.0|~2.0",
         "elasticsearch/elasticsearch": "~5.0"
     },
     "suggest": {