diff --git a/htdocs/core/class/html.form.class.php b/htdocs/core/class/html.form.class.php
index 321a475200698..59142e4c06051 100644
--- a/htdocs/core/class/html.form.class.php
+++ b/htdocs/core/class/html.form.class.php
@@ -5458,6 +5458,14 @@ function showLinkToObjectBlock($object, $restrictlinksto=array(), $excludelinkst
 		{
     		$listofidcompanytoscan=$object->thirdparty->id;
     		if (($object->thirdparty->parent > 0) && ! empty($conf->global->THIRDPARTY_INCLUDE_PARENT_IN_LINKTO)) $listofidcompanytoscan.=','.$object->thirdparty->parent;
+			if (($object->fk_project > 0) && ! empty($conf->global->THIRDPARTY_INCLUDE_PROJECT_THIRDPARY_IN_LINKTO))
+			{
+				include_once DOL_DOCUMENT_ROOT.'/projet/class/project.class.php';
+				$tmpproject=new Project($this->db);
+				$tmpproject->fetch($object->fk_project);
+				if ($tmpproject->socid > 0 && ($tmpproject->socid != $object->thirdparty->id)) $listofidcompanytoscan.=','.$tmpproject->socid;
+				unset($tmpproject);
+			}
 
     		$possiblelinks=array(
     		    'propal'=>array('enabled'=>$conf->propal->enabled, 'perms'=>1, 'label'=>'LinkToProposal', 'sql'=>"SELECT s.rowid as socid, s.nom as name, s.client, t.rowid, t.ref, t.ref_client, t.total_ht FROM ".MAIN_DB_PREFIX."societe as s, ".MAIN_DB_PREFIX."propal as t WHERE t.fk_soc = s.rowid AND t.fk_soc IN (".$listofidcompanytoscan.') AND t.entity IN ('.getEntity('propal',1).')'),