diff --git a/Validator/ProductVariantCombinationValidator.php b/Validator/ProductVariantCombinationValidator.php
index 886721350736..77dac54b4ac7 100644
--- a/Validator/ProductVariantCombinationValidator.php
+++ b/Validator/ProductVariantCombinationValidator.php
@@ -13,11 +13,13 @@
 
 namespace Sylius\Bundle\ProductBundle\Validator;
 
+use Sylius\Bundle\ProductBundle\Validator\Constraint\ProductVariantCombination;
 use Sylius\Component\Product\Checker\ProductVariantsParityCheckerInterface;
 use Sylius\Component\Product\Model\ProductVariantInterface;
 use Symfony\Component\Validator\Constraint;
 use Symfony\Component\Validator\ConstraintValidator;
 use Symfony\Component\Validator\Exception\UnexpectedTypeException;
+use Webmozart\Assert\Assert;
 
 final class ProductVariantCombinationValidator extends ConstraintValidator
 {
@@ -39,6 +41,9 @@ public function __construct(ProductVariantsParityCheckerInterface $variantsParit
      */
     public function validate($value, Constraint $constraint): void
     {
+        /** @var ProductVariantCombination $constraint */
+        Assert::isInstanceOf($constraint, ProductVariantCombination::class);
+
         if (!$value instanceof ProductVariantInterface) {
             throw new UnexpectedTypeException($value, ProductVariantInterface::class);
         }
diff --git a/Validator/UniqueSimpleProductCodeValidator.php b/Validator/UniqueSimpleProductCodeValidator.php
index 488ec30b6e71..15dd3a28f6a4 100644
--- a/Validator/UniqueSimpleProductCodeValidator.php
+++ b/Validator/UniqueSimpleProductCodeValidator.php
@@ -13,11 +13,14 @@
 
 namespace Sylius\Bundle\ProductBundle\Validator;
 
+use Sylius\Bundle\ProductBundle\Validator\Constraint\UniqueSimpleProductCode;
 use Sylius\Component\Product\Model\ProductInterface;
+use Sylius\Component\Product\Model\ProductVariantInterface;
 use Sylius\Component\Product\Repository\ProductVariantRepositoryInterface;
 use Symfony\Component\Validator\Constraint;
 use Symfony\Component\Validator\ConstraintValidator;
 use Symfony\Component\Validator\Exception\UnexpectedTypeException;
+use Webmozart\Assert\Assert;
 
 final class UniqueSimpleProductCodeValidator extends ConstraintValidator
 {
@@ -39,6 +42,9 @@ public function __construct(ProductVariantRepositoryInterface $productVariantRep
      */
     public function validate($value, Constraint $constraint): void
     {
+        /** @var UniqueSimpleProductCode $constraint */
+        Assert::isInstanceOf($constraint, UniqueSimpleProductCode::class);
+
         if (!$value instanceof ProductInterface) {
             throw new UnexpectedTypeException($value, ProductInterface::class);
         }
@@ -47,6 +53,7 @@ public function validate($value, Constraint $constraint): void
             return;
         }
 
+        /** @var ProductVariantInterface $existingProductVariant */
         $existingProductVariant = $this->productVariantRepository->findOneBy(['code' => $value->getCode()]);
 
         if (null !== $existingProductVariant && $existingProductVariant->getProduct()->getId() !== $value->getId()) {