diff --git a/htdocs/projet/class/project.class.php b/htdocs/projet/class/project.class.php
index 7548f4f2e0a114c035ffb695406d7941becc41c8..7f8aa6252e852a7c48f88c90cb2339e17771242e 100644
--- a/htdocs/projet/class/project.class.php
+++ b/htdocs/projet/class/project.class.php
@@ -1146,14 +1146,21 @@ class Project extends CommonObject
 		//Generate next ref
 		$defaultref='';
     	$obj = empty($conf->global->PROJECT_ADDON)?'mod_project_simple':$conf->global->PROJECT_ADDON;
-    	if (! empty($conf->global->PROJECT_ADDON) && is_readable(DOL_DOCUMENT_ROOT ."/core/modules/project/".$conf->global->PROJECT_ADDON.".php"))
+    	// Search template files
+    	$file=''; $classname=''; $filefound=0;
+    	$dirmodels=array_merge(array('/'),(array) $conf->modules_parts['models']);
+    	foreach($dirmodels as $reldir)
     	{
-
-        	require_once DOL_DOCUMENT_ROOT ."/core/modules/project/".$conf->global->PROJECT_ADDON.'.php';
-        	$modProject = new $obj;
-        	$defaultref = $modProject->getNextValue(is_object($clone_project->thirdparty)?$clone_project->thirdparty->id:0,$clone_project);
+    	    $file=dol_buildpath($reldir."core/modules/project/".$obj.'.php',0);
+    	    if (file_exists($file))
+    	    {
+    	        $filefound=1;
+    	        dol_include_once($reldir."core/modules/project/".$obj.'.php');
+            	$modProject = new $obj;
+            	$defaultref = $modProject->getNextValue(is_object($clone_project->thirdparty)?$clone_project->thirdparty:null, $clone_project);
+            	break;
+    	    }
     	}
-
     	if (is_numeric($defaultref) && $defaultref <= 0) $defaultref='';
 
 		$clone_project->ref=$defaultref;