diff --git a/composer.json b/composer.json
index dee322f..80659a4 100644
--- a/composer.json
+++ b/composer.json
@@ -13,10 +13,10 @@
     "require": {
         "php": ">=7.2",
         "ddeboer/vatin": "^2.0",
-        "symfony/http-kernel": "^4.0 || ^5.0 || ^6.0",
-        "symfony/dependency-injection": "^4.0 || ^5.0 || ^6.0",
-        "symfony/config": "^4.0 || ^5.0 || ^6.0",
-        "symfony/validator": "^4.0 || ^5.0 || ^6.0"
+        "symfony/http-kernel": "^4.0 || ^5.0 || ^6.0 || ^7.0",
+        "symfony/dependency-injection": "^4.0 || ^5.0 || ^6.0 || ^7.0",
+        "symfony/config": "^4.0 || ^5.0 || ^6.0 || ^7.0",
+        "symfony/validator": "^4.0 || ^5.0 || ^6.0 || ^7.0"
     },
     "require-dev": {
         "roave/security-advisories": "dev-latest",
diff --git a/src/Validator/Constraints/Vatin.php b/src/Validator/Constraints/Vatin.php
index 77cbf92..5ed3631 100644
--- a/src/Validator/Constraints/Vatin.php
+++ b/src/Validator/Constraints/Vatin.php
@@ -41,7 +41,7 @@ public function __construct(
         parent::__construct($options ?? [], $groups, $payload);
     }
 
-    public function validatedBy()
+    public function validatedBy(): string
     {
         return 'ddeboer_vatin.validator';
     }