diff --git a/htdocs/variants/class/ProductCombination.class.php b/htdocs/variants/class/ProductCombination.class.php
index 23bdfcc9441..42e3bdc1530 100644
--- a/htdocs/variants/class/ProductCombination.class.php
+++ b/htdocs/variants/class/ProductCombination.class.php
@@ -83,6 +83,16 @@ class ProductCombination
 	 */
 	public $variation_ref_ext = '';
 
+	/**
+	 * @var string error
+	 */
+	public $error;
+
+	/**
+	 * @var string[] array of errors
+	 */
+	public $errors = array();
+
 	/**
 	 * Constructor
 	 *
@@ -1043,6 +1053,16 @@ class ProductCombinationLevel
 	 */
 	public $variation_price_percentage = false;
 
+	/**
+	 * @var string error
+	 */
+	public $error;
+
+	/**
+	 * @var string[] array of errors
+	 */
+	public $errors = array();
+
 	/**
 	 * Constructor
 	 *
@@ -1114,7 +1134,7 @@ class ProductCombinationLevel
 	/**
 	 * Assign vars form an stdclass like sql obj
 	 *
-	 * @param 	int 	$obj		Object resultset
+	 * @param 	Object 	$obj		Object resultset
 	 * @return 	int 				<0 KO, >0 OK
 	 */
 	public function fetchFormObj($obj)
diff --git a/htdocs/variants/class/ProductCombination2ValuePair.class.php b/htdocs/variants/class/ProductCombination2ValuePair.class.php
index 5f4ab8480a5..15c2a11ddd9 100644
--- a/htdocs/variants/class/ProductCombination2ValuePair.class.php
+++ b/htdocs/variants/class/ProductCombination2ValuePair.class.php
@@ -52,6 +52,16 @@ class ProductCombination2ValuePair
 	 */
 	public $fk_prod_attr_val;
 
+	/**
+	 * @var string error
+	 */
+	public $error;
+
+	/**
+	 * @var string[] array of errors
+	 */
+	public $errors = array();
+
 	/**
 	 * Constructor
 	 *