diff --git a/language/constants.xml b/language/constants.xml
index f4e88b165b..0e2748b83a 100644
--- a/language/constants.xml
+++ b/language/constants.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.39 $ -->
+<!-- $Revision: 1.40 $ -->
  <chapter id="language.constants">
   <title>Constants</title>
 
@@ -190,6 +190,9 @@ echo Constant; // outputs "Constant" and issues a notice.
         <entry>
          The full path and filename of the file.  If used inside an include,
          the name of the included file is returned.
+         Since PHP 4.0.2, <constant>__FILE__</constant> always contains an
+         absolute path whereas in older versions it contained relative path
+         under some circumstances.
         </entry>
        </row>
        <row>