diff --git a/src/PhpGenerator/Constant.php b/src/PhpGenerator/Constant.php
index 44c1938c..a959efa5 100644
--- a/src/PhpGenerator/Constant.php
+++ b/src/PhpGenerator/Constant.php
@@ -53,7 +53,8 @@ public function isFinal(): bool
 
 	public function setType(?string $type): static
 	{
-		$this->type = Helpers::validateType($type);
+		Helpers::validateType($type);
+		$this->type = $type;
 		return $this;
 	}
 
diff --git a/tests/PhpGenerator/ClassType.phpt b/tests/PhpGenerator/ClassType.phpt
index a8e81eee..e22c3720 100644
--- a/tests/PhpGenerator/ClassType.phpt
+++ b/tests/PhpGenerator/ClassType.phpt
@@ -39,7 +39,7 @@ $trait2 = $class->addTrait('AnotherTrait')
 $class->addConstant('ROLE', 'admin');
 $class->addConstant('ACTIVE', false)
 	->setFinal()
-	->setType('bool');
+	->setType('?bool');
 Assert::true($class->hasConstant('ROLE'));
 Assert::false($class->hasConstant('xxx'));
 
diff --git a/tests/PhpGenerator/expected/ClassType.expect b/tests/PhpGenerator/expected/ClassType.expect
index 80cef326..642dfb17 100644
--- a/tests/PhpGenerator/expected/ClassType.expect
+++ b/tests/PhpGenerator/expected/ClassType.expect
@@ -17,7 +17,7 @@ abstract class Example extends ParentClass implements IExample, IOne
 	}
 
 	public const ROLE = 'admin';
-	final public const bool ACTIVE = false;
+	final public const ?bool ACTIVE = false;
 
 	/** Commented */
 	private const FORCE_ARRAY = Nette\Utils\Json::FORCE_ARRAY;