diff --git a/upload/catalog/model/extension/total/coupon.php b/upload/catalog/model/extension/total/coupon.php
index f1d6be49a..badd3bacc 100644
--- a/upload/catalog/model/extension/total/coupon.php
+++ b/upload/catalog/model/extension/total/coupon.php
@@ -149,7 +149,7 @@ public function getTotal(array $total): void {
 					}
 
 					if ($status) {
-						if ($coupon_info['type'] == 'F') {
+						if ($coupon_info['type'] == 'F' && $sub_total) {
 							$discount = $coupon_info['discount'] * ($product['total'] / $sub_total);
 						} elseif ($coupon_info['type'] == 'P') {
 							$discount = $product['total'] / 100 * $coupon_info['discount'];