diff --git a/NEWS b/NEWS
index bde58645..a054a15b 100644
--- a/NEWS
+++ b/NEWS
@@ -1,4 +1,4 @@
-  - remove DIR_SEP, use DIRECTORY_SEPARATOR exclusively (Monte)
+  - use DIRECTORY_SEPARATOR exclusively, keep DIR_SEP for BC (Monte)
   - changed "link" to "href" in html_image. "link" is still working
     but deprecated (messju)
   - html_image always renders an alt-tag now (default alt="") (messju)
diff --git a/libs/Smarty.class.php b/libs/Smarty.class.php
index fd230cbb..42b2af02 100644
--- a/libs/Smarty.class.php
+++ b/libs/Smarty.class.php
@@ -50,6 +50,10 @@
  * application has not already defined it.
  */
 
+if(!defined('DIR_SEP')) {
+	define('DIR_SEP', DIRECTORY_SEPARATOR);
+}
+
 /**
  * Sets SMARTY_DIR only if user application has not already defined it
  */