diff --git a/appendices/debugger.xml b/appendices/debugger.xml
index 652212b840..2b0343bdaa 100644
--- a/appendices/debugger.xml
+++ b/appendices/debugger.xml
@@ -42,6 +42,12 @@
     socket, <emphasis>even if you them turned off with
     <function>error_reporting</function></emphasis>.  
    </para>
+   <note>
+    <para>
+	 The code for the debugger has not been ported to PHP4, at the
+	 present time only PHP3 supports the debugger code.
+	</para>
+   </note>
   </sect1>
 
   <sect1 id="debugger-protocol">