diff --git a/reference/session/functions/session-set-save-handler.xml b/reference/session/functions/session-set-save-handler.xml
index ac9d267079..3754be7312 100644
--- a/reference/session/functions/session-set-save-handler.xml
+++ b/reference/session/functions/session-set-save-handler.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.3 $ -->
+<!-- $Revision: 1.4 $ -->
 <!-- splitted from ./en/functions/session.xml, last change in rev 1.23 -->
   <refentry id="function.session-set-save-handler">
    <refnamediv>
@@ -39,6 +39,14 @@
       written to a file instead.
      </para>
     </note>
+    <note>
+     <para>
+      The write handler is not executed if the session contains no data;
+      this applies even if empty session variables are registered. This
+      differs to the default file-based session save handler, which creates
+      empty session files.
+     </para>
+    </note>
     <para>
      The following example provides file based session
      storage similar to the PHP sessions default save handler