diff --git a/appendices/migration52.xml b/appendices/migration52.xml
index 63e05f7e46..e76fbf124b 100644
--- a/appendices/migration52.xml
+++ b/appendices/migration52.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.8 $ -->
+<!-- $Revision: 1.9 $ -->
 <appendix id="migration52">
  <title>Migrating from PHP 5.1.x to PHP 5.2.x</title>
 
@@ -1574,6 +1574,18 @@ $obj->getCommentName('');
    </listitem>
   </itemizedlist>
 
+  <para><link linkend="ref.gmp">GMP</link>:</para>
+  <itemizedlist>
+   <listitem>
+    <simpara>
+     <constant>GMP_VERSION</constant>
+    </simpara>
+    <simpara>
+     Added in PHP 5.2.2.
+    </simpara>
+   </listitem>
+  </itemizedlist>
+
   <para><link linkend="ref.ming">ming</link>:</para>
   <itemizedlist>
    <listitem>
diff --git a/reference/gmp/constants.xml b/reference/gmp/constants.xml
index 6c58c0ba57..6f7e706f7e 100644
--- a/reference/gmp/constants.xml
+++ b/reference/gmp/constants.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.3 $ -->
+<!-- $Revision: 1.4 $ -->
 <section id="gmp.constants">
  &reftitle.constants;
  &extension.constants;
@@ -37,6 +37,17 @@
     </simpara>
    </listitem>
   </varlistentry>
+  <varlistentry>
+   <term>
+    <constant>GMP_VERSION</constant>
+    (<type>string</type>)
+   </term>
+   <listitem>
+    <simpara>
+     The GMP library version
+    </simpara>
+   </listitem>
+  </varlistentry>
  </variablelist>
 </section>