diff --git a/htdocs/contrat/card.php b/htdocs/contrat/card.php
index 5c9ac3375dd..0bf304b96a1 100644
--- a/htdocs/contrat/card.php
+++ b/htdocs/contrat/card.php
@@ -433,7 +433,7 @@ if (empty($reshook))
 		}
 
 		$qty = GETPOST('qty'.$predef);
-		$remise_percent = GETPOST('remise_percent'.$predef);
+		$remise_percent = ((GETPOST('remise_percent'.$predef) != '') ? GETPOST('remise_percent'.$predef) : 0);
 
 		if ($qty == '')
 		{
@@ -566,7 +566,8 @@ if (empty($reshook))
 			$info_bits=0;
 			if ($tva_npr) $info_bits |= 0x01;
 
-			if (((!empty($conf->global->MAIN_USE_ADVANCED_PERMS) && empty($user->rights->produit->ignore_price_min_advance)) || empty($conf->global->MAIN_USE_ADVANCED_PERMS) )&& ($price_min && (price2num($pu_ht)*(1-price2num($remise_percent)/100) < price2num($price_min))))
+			if (((! empty($conf->global->MAIN_USE_ADVANCED_PERMS) && empty($user->rights->produit->ignore_price_min_advance))
+				|| empty($conf->global->MAIN_USE_ADVANCED_PERMS) ) && ($price_min && (price2num($pu_ht)*(1-price2num($remise_percent)/100) < price2num($price_min))))
 			{
 				$object->error = $langs->trans("CantBeLessThanMinPrice", price(price2num($price_min, 'MU'), 0, $langs, 0, 0, -1, $conf->currency));
 				$result = -1 ;