diff --git a/composer.json b/composer.json
index 6d4a8dc09..a3bb333aa 100644
--- a/composer.json
+++ b/composer.json
@@ -18,7 +18,7 @@
 		"php": ">=7.2 <8.3",
 		"nette/component-model": "^3.0",
 		"nette/http": "^3.1",
-		"nette/utils": "^3.2.1"
+		"nette/utils": "^3.2.5 || ~4.0.0"
 	},
 	"require-dev": {
 		"nette/application": "^3.0",
diff --git a/src/Forms/Container.php b/src/Forms/Container.php
index 1eca7c5c1..70294a4a3 100644
--- a/src/Forms/Container.php
+++ b/src/Forms/Container.php
@@ -167,7 +167,7 @@ public function getUntrustedValues($returnType = ArrayHash::class, ?array $contr
 			} elseif ($control instanceof self) {
 				$type = $returnType === self::Array && !$control->mappedType
 					? self::Array
-					: ($rc->hasProperty($name) ? Nette\Utils\Reflection::getPropertyType($rc->getProperty($name)) : null);
+					: ($rc->hasProperty($name) ? Helpers::getSingleType($rc->getProperty($name)) : null);
 				$obj->$name = $control->getUntrustedValues($type, $allowed ? null : $controls);
 			}
 		}
@@ -237,7 +237,7 @@ public function validate(?array $controls = null): void
 
 		foreach ($this->onValidate as $handler) {
 			$params = Nette\Utils\Callback::toReflection($handler)->getParameters();
-			$types = array_map([Nette\Utils\Reflection::class, 'getParameterType'], $params);
+			$types = array_map([Helpers::class, 'getSingleType'], $params);
 			$args = isset($types[0]) && !$this instanceof $types[0]
 				? [$this->getUntrustedValues($types[0])]
 				: [$this, isset($params[1]) ? $this->getUntrustedValues($types[1]) : null];
diff --git a/src/Forms/Form.php b/src/Forms/Form.php
index f294479b1..b2a252fbc 100644
--- a/src/Forms/Form.php
+++ b/src/Forms/Form.php
@@ -447,7 +447,7 @@ private function invokeHandlers(iterable $handlers, $button = null): void
 	{
 		foreach ($handlers as $handler) {
 			$params = Nette\Utils\Callback::toReflection($handler)->getParameters();
-			$types = array_map([Nette\Utils\Reflection::class, 'getParameterType'], $params);
+			$types = array_map([Helpers::class, 'getSingleType'], $params);
 			if (!isset($types[0])) {
 				$arg0 = $button ?: $this;
 			} elseif ($this instanceof $types[0]) {
diff --git a/src/Forms/Helpers.php b/src/Forms/Helpers.php
index f63feae41..4a15baef5 100644
--- a/src/Forms/Helpers.php
+++ b/src/Forms/Helpers.php
@@ -184,7 +184,7 @@ public static function createInputList(
 			$input->value = $value;
 			$res .= ($res === '' && $wrapperEnd === '' ? '' : $wrapper)
 				. $labelTag . $label->attributes() . '>'
-				. $inputTag . $input->attributes() . (Html::$xhtml ? ' />' : '>')
+				. $inputTag . $input->attributes() . (isset(Html::$xhtml) && Html::$xhtml ? ' />' : '>')
 				. ($caption instanceof Nette\HtmlStringable ? $caption : htmlspecialchars((string) $caption, ENT_NOQUOTES, 'UTF-8'))
 				. '</label>'
 				. $wrapperEnd;
@@ -269,4 +269,20 @@ public static function iniGetSize(string $name): int
 			? (int) $value << $units[$ch]
 			: (int) $value;
 	}
+
+
+	/** @internal */
+	public static function getSingleType($reflection): ?string
+	{
+		$type = Nette\Utils\Type::fromReflection($reflection);
+		if (!$type) {
+			return null;
+		} elseif ($res = $type->getSingleName()) {
+			return $res;
+		} else {
+			throw new Nette\InvalidStateException(
+				Nette\Utils\Reflection::toString($reflection) . " has unsupported type '$type'."
+			);
+		}
+	}
 }