diff --git a/htdocs/supplier_proposal/card.php b/htdocs/supplier_proposal/card.php
index 8d100370a00..072e1bfdf5b 100644
--- a/htdocs/supplier_proposal/card.php
+++ b/htdocs/supplier_proposal/card.php
@@ -586,7 +586,7 @@ if (empty($reshook)) {
 			$error++;
 		}
 
-		if ($prod_entry_mode == 'free' && (empty($idprod) || $idprod < 0) && GETPOST('price_ht') === '' && GETPOST('price_ttc') === '' && $price_ht_devise === '') { 	// Unit price can be 0 but not ''. Also price can be negative for proposal.
+		if ($prod_entry_mode == 'free' && (empty($idprod) || $idprod < 0) && GETPOST('price_ht') === '' && GETPOST('price_ttc') === '' && GETPOST('multicurrency_price_ht') === '') { 	// Unit price can be 0 but not ''. Also price can be negative for proposal.
 			setEventMessages($langs->trans("ErrorFieldRequired", $langs->transnoentitiesnoconv("UnitPrice")), null, 'errors');
 			$error++;
 		}