diff --git a/composer.json b/composer.json
index 1a293a60..1bd65802 100644
--- a/composer.json
+++ b/composer.json
@@ -11,14 +11,14 @@
   "require": {
     "php": ">=8.2",
     "ext-fileinfo": "*",
-    "ipl/stdlib": ">=0.12.0",
+    "ipl/stdlib": "dev-modernize-code-with-breaking-changes",
     "ipl/validator": ">=0.5.0",
     "psr/http-message": "^1.1",
     "guzzlehttp/psr7": "^2.8"
   },
   "require-dev": {
     "ext-dom": "*",
-    "ipl/stdlib": "dev-main",
+    "ipl/stdlib": "dev-modernize-code-with-breaking-changes",
     "ipl/validator": "dev-main"
   },
   "autoload": {
diff --git a/src/FormElement/FormElements.php b/src/FormElement/FormElements.php
index 6121b762..3f0b41dd 100644
--- a/src/FormElement/FormElements.php
+++ b/src/FormElement/FormElements.php
@@ -536,7 +536,7 @@ protected function decorate(FormElement $element)
         return $this;
     }
 
-    public function isValidEvent($event)
+    public function isValidEvent(string $event): bool
     {
         return in_array($event, [
             Form::ON_SUBMIT,