diff --git a/ChangeLog b/ChangeLog
index 3bb088b99f3..ed85d409840 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -113,6 +113,7 @@ Fix: [ bug #1306 ] Fatal error when adding an external calendar.
 New: Added es_CL language
 Fix: Margin tabs bad data show
 Fix: [ bug #1318 ] Problem with enter key when adding an existing product to a customer invoice.
+Fix: [ bug #1410 ] Add customer order line asks for required Unit Price but doesn't interrupt the creation of the line
 
 ***** ChangeLog for 3.5 compared to 3.4.* *****
 For users:
diff --git a/htdocs/commande/fiche.php b/htdocs/commande/fiche.php
index 10856f27c5e..4a00c1a661b 100644
--- a/htdocs/commande/fiche.php
+++ b/htdocs/commande/fiche.php
@@ -617,27 +617,27 @@ else if ($action == 'addline' && $user->rights->commande->creer)
 	if ((empty($idprod) || GETPOST('usenewaddlineform')) && ($price_ht < 0) && ($qty < 0))
 	{
 		setEventMessage($langs->trans('ErrorBothFieldCantBeNegative', $langs->transnoentitiesnoconv('UnitPriceHT'), $langs->transnoentitiesnoconv('Qty')), 'errors');
-		$error++;
+		$error = true;
 	}
 	if (empty($idprod) && GETPOST('type') < 0)
 	{
 		setEventMessage($langs->trans('ErrorFieldRequired', $langs->transnoentitiesnoconv('Type')), 'errors');
-		$error++;
+		$error = true;
 	}
 	if ((empty($idprod) || GETPOST('usenewaddlineform')) && (!($price_ht >= 0) || $price_ht == ''))	// Unit price can be 0 but not ''
 	{
 		setEventMessage($langs->trans("ErrorFieldRequired",$langs->transnoentitiesnoconv("UnitPriceHT")), 'errors');
-		$error++;
+		$error = true;
 	}
 	if ($qty == '')
 	{
 		setEventMessage($langs->trans('ErrorFieldRequired', $langs->transnoentitiesnoconv('Qty')), 'errors');
-		$error++;
+		$error = true;
 	}
 	if (empty($idprod) && empty($product_desc))
 	{
 		setEventMessage($langs->trans('ErrorFieldRequired', $langs->transnoentitiesnoconv('Description')), 'errors');
-		$error++;
+		$error = true;
 	}
 
 	if (! $error && ($qty >= 0) && (! empty($product_desc) || ! empty($idprod)))