diff --git a/htdocs/variants/class/ProductCombination.class.php b/htdocs/variants/class/ProductCombination.class.php
index f1b10559898..f94a5ac3154 100644
--- a/htdocs/variants/class/ProductCombination.class.php
+++ b/htdocs/variants/class/ProductCombination.class.php
@@ -264,7 +264,7 @@ class ProductCombination
 			$this->fetchCombinationPriceLevels();
 		}
 
-		return $this->fk_product_parent;
+		return (int) $this->fk_product_parent;
 	}
 
 	/**