diff --git a/htdocs/compta/facture/class/facture.class.php b/htdocs/compta/facture/class/facture.class.php
index fec912c296d..25f8aceb26e 100644
--- a/htdocs/compta/facture/class/facture.class.php
+++ b/htdocs/compta/facture/class/facture.class.php
@@ -2222,10 +2222,9 @@ class Facture extends CommonObject
 		$langs->load("bills");
 
 		// Clean parameters (if not defined or using deprecated value)
-		if (empty($conf->global->FACTURE_ADDON) || $conf->global->FACTURE_ADDON=='terre')
-		{
-			$conf->global->FACTURE_ADDON='mod_facture_terre';
-		}
+		if (empty($conf->global->FACTURE_ADDON)) $conf->global->FACTURE_ADDON='mod_facture_terre';
+		else if ($conf->global->FACTURE_ADDON=='terre') $conf->global->FACTURE_ADDON='mod_facture_terre';
+		else if ($conf->global->FACTURE_ADDON=='mercure') $conf->global->FACTURE_ADDON='mod_mercure_terre';
 
 		$mybool=false;