diff --git a/src/Validator/Inject/Length.php b/src/Validator/Inject/Length.php
index 9c46536..7cd2e41 100644
--- a/src/Validator/Inject/Length.php
+++ b/src/Validator/Inject/Length.php
@@ -26,6 +26,6 @@ class Length implements ValidatorInterface
 	public function dispatch(object $class, string $name): bool
 	{
 		// TODO: Implement dispatch() method.
-		return mb_strlen($class->{$name}) === $this->value;
+		return mb_strlen((string)$class->{$name}) === $this->value;
 	}
 }
diff --git a/src/Validator/Inject/MaxLength.php b/src/Validator/Inject/MaxLength.php
index 0fde4cc..8af4b86 100644
--- a/src/Validator/Inject/MaxLength.php
+++ b/src/Validator/Inject/MaxLength.php
@@ -26,6 +26,6 @@ class MaxLength implements ValidatorInterface
 	public function dispatch(object $class, string $name): bool
 	{
 		// TODO: Implement dispatch() method.
-		return mb_strlen($class->{$name}) <= $this->value;
+		return mb_strlen((string)$class->{$name}) <= $this->value;
 	}
 }
diff --git a/src/Validator/Inject/MinLength.php b/src/Validator/Inject/MinLength.php
index 0eaaf53..46973cb 100644
--- a/src/Validator/Inject/MinLength.php
+++ b/src/Validator/Inject/MinLength.php
@@ -26,6 +26,6 @@ class MinLength implements ValidatorInterface
 	public function dispatch(object $class, string $name): bool
 	{
 		// TODO: Implement dispatch() method.
-		return mb_strlen($class->{$name}) <= $this->value;
+		return mb_strlen((string)$class->{$name}) <= $this->value;
 	}
 }