diff --git a/appendices/debugger.xml b/appendices/debugger.xml
index d6b2301226..2bc91f07e0 100644
--- a/appendices/debugger.xml
+++ b/appendices/debugger.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.18 $ -->
+<!-- $Revision: 1.19 $ -->
  <appendix id="debugger">
   <title>Debugging PHP</title>
 
@@ -12,8 +12,9 @@
     PHP 4 does not have an internal debugging facility.
     You can use one of the external debuggers though. The
     <ulink url="&url.zend.ide;">Zend IDE</ulink> includes
-    a debugger, and there is also a free debugger extension
-    named DBG at <ulink url="&url.dbg;">&url.dbg;</ulink>.
+    a debugger, and there are also some free debugger extensions
+    like DBG at <ulink url="&url.dbg;">&url.dbg;</ulink> or the 
+    <ulink url="&url.apd;">Advanced PHP Debugger</ulink> (APD).
    </simpara>
   </sect1>