diff --git a/src/Model/Product/ProductVariant.php b/src/Model/Product/ProductVariant.php
index fd113e43c6..5673962928 100644
--- a/src/Model/Product/ProductVariant.php
+++ b/src/Model/Product/ProductVariant.php
@@ -47,7 +47,7 @@ public function fieldDefinitions()
     {
         return [
             'id' => [static::TYPE => 'int'],
-            'sku' => [static::TYPE => 'int'],
+            'sku' => [static::TYPE => 'string'],
             'prices' => [static::TYPE => '\Commercetools\Core\Model\Common\PriceCollection'],
             'price' => [static::TYPE => '\Commercetools\Core\Model\Common\Price'],
             'attributes' => [static::TYPE => '\Commercetools\Core\Model\Common\AttributeCollection'],