diff --git a/htdocs/core/conf.class.php b/htdocs/core/conf.class.php
index 8ed545028e9..92053bb87dd 100644
--- a/htdocs/core/conf.class.php
+++ b/htdocs/core/conf.class.php
@@ -84,6 +84,8 @@ class Conf
 		
 		// Add root path
 		$this->include_path[] = DOL_DOCUMENT_ROOT."/";
+		// Add core path
+		$this->include_path[] = DOL_DOCUMENT_ROOT."/core/";
 		// Add library path
 		$this->include_path[] = DOL_DOCUMENT_ROOT."/lib/";