diff -u b/modules/product/src/Entity/ProductType.php b/modules/product/src/Entity/ProductType.php
--- b/modules/product/src/Entity/ProductType.php
+++ b/modules/product/src/Entity/ProductType.php
@@ -108,7 +108,7 @@
   /**
    * {@inheritdoc}
    */
-  public function setDescription($description) : self {
+  public function setDescription($description) : ProductTypeInterface {
     $this->description = $description;
     return $this;
   }