diff --git a/reference/image/constants.xml b/reference/image/constants.xml
index 62ef953cbd..3abfcd5330 100644
--- a/reference/image/constants.xml
+++ b/reference/image/constants.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.14 $ -->
+<!-- $Revision: 1.15 $ -->
 <appendix xml:id="image.constants" xmlns="http://docbook.org/ns/docbook">
  &reftitle.constants;
  &extension.constants;
@@ -69,6 +69,19 @@
    </listitem>
   </varlistentry>
 
+  <varlistentry>
+   <term>
+    <constant>GD_BUNDLE</constant>
+    (<type>integer</type>)
+   </term>
+   <listitem>
+    <simpara>
+     When the bundled version of GD is used this is 1 otherwise 
+     its set to 0.
+    </simpara>
+   </listitem>
+  </varlistentry>
+
   <varlistentry>
    <term>
     <constant>IMG_GIF</constant>