diff --git a/htdocs/core/class/commondocgenerator.class.php b/htdocs/core/class/commondocgenerator.class.php
index 9a1dddd2899..ba90df80676 100755
--- a/htdocs/core/class/commondocgenerator.class.php
+++ b/htdocs/core/class/commondocgenerator.class.php
@@ -23,7 +23,7 @@
  *	    \file       htdocs/core/class/commondocgenerator.class.php
  *		\ingroup    core
  *		\brief      File of parent class for documents generators
- *		\version    $Id: commondocgenerator.class.php,v 1.7 2011/07/31 23:45:13 eldy Exp $
+ *		\version    $Id: commondocgenerator.class.php,v 1.8 2011/08/22 22:11:53 eldy Exp $
  */
 
 
@@ -31,7 +31,7 @@
  *	\class      CommonDocGenerator
  *	\brief      Parent class for documents generators
  */
-class CommonDocGenerator
+abstract class CommonDocGenerator
 {
 	var $error='';
 
diff --git a/htdocs/core/class/commonobjectline.class.php b/htdocs/core/class/commonobjectline.class.php
index e61160aac38..d9191532fea 100644
--- a/htdocs/core/class/commonobjectline.class.php
+++ b/htdocs/core/class/commonobjectline.class.php
@@ -19,7 +19,7 @@
  *       \file       htdocs/core/class/commonobjectline.class.php
  *       \ingroup    core
  *       \brief      File of the superclass of classes of lines of business objects (invoice, contract, PROPAL, commands, etc. ...)
- *       \version    $Id: commonobjectline.class.php,v 1.5 2011/07/31 23:45:14 eldy Exp $
+ *       \version    $Id: commonobjectline.class.php,v 1.6 2011/08/22 22:11:54 eldy Exp $
  */
 
 
@@ -28,7 +28,7 @@
  *       \brief 		Superclass for class inheritance lines of business objects
  */
 
-class CommonObjectLine
+abstract class CommonObjectLine
 {
 
 }