diff --git a/htdocs/commande/card.php b/htdocs/commande/card.php
index 3c1bf672c0f..d4855e8933f 100644
--- a/htdocs/commande/card.php
+++ b/htdocs/commande/card.php
@@ -2556,7 +2556,7 @@ if ($action == 'create' && $usercancreate)
 				}
 
 				// Valid
-				if ($object->statut == Commande::STATUS_DRAFT && $object->total_ttc >= 0 && $numlines > 0 && $usercanvalidate)
+				if ($object->statut == Commande::STATUS_DRAFT && ($object->total_ttc >= 0 || ! empty($conf->global->ORDER_ENABLE_NEGATIVE))  && $numlines > 0 && $usercanvalidate)
 				{
 					print '<a class="butAction" href="'.$_SERVER["PHP_SELF"].'?id='.$object->id.'&amp;action=validate">'.$langs->trans('Validate').'</a>';
 				}
@@ -2631,7 +2631,7 @@ if ($action == 'create' && $usercancreate)
 
 				// Create bill and Classify billed
 				// Note: Even if module invoice is not enabled, we should be able to use button "Classified billed"
-				if ($object->statut > Commande::STATUS_DRAFT && !$object->billed) {
+				if ($object->statut > Commande::STATUS_DRAFT && !$object->billed && $object->total_ttc >= 0) {
 					if (!empty($conf->facture->enabled) && $user->rights->facture->creer && empty($conf->global->WORKFLOW_DISABLE_CREATE_INVOICE_FROM_ORDER)) {
 						print '<div class="inline-block divButAction"><a class="butAction" href="'.DOL_URL_ROOT.'/compta/facture/card.php?action=create&amp;origin='.$object->element.'&amp;originid='.$object->id.'&amp;socid='.$object->socid.'">'.$langs->trans("CreateBill").'</a></div>';
 					}