diff --git a/docs/dtd/plugin/2.0.0-01.dtd b/docs/dtd/plugin/2.0.0-01.dtd
index 62907f9481..23441a5a63 100644
--- a/docs/dtd/plugin/2.0.0-01.dtd
+++ b/docs/dtd/plugin/2.0.0-01.dtd
@@ -88,7 +88,10 @@
 <!-- generated entries -->
 
 <!--- extension -->
-<!ELEMENT extension (description|class)*>
+<!ELEMENT extension (description|class|requires)*>
+
+<!--- requires value -->
+<!ELEMENT requires (#PCDATA)>
 
 <!--- class value -->
 <!ELEMENT class (#PCDATA)>