diff --git a/ws/Xmlmind/Patch/040_hdmBusinessIntegrityRules.patch b/ws/Xmlmind/Patch/040_hdmBusinessIntegrityRules.patch
index 5525d729dedb6e8d69e84109bc7c6860e60a5e54..362345b7c6e9e834e84e58c46b0616a321b4d35c 100644
--- a/ws/Xmlmind/Patch/040_hdmBusinessIntegrityRules.patch
+++ b/ws/Xmlmind/Patch/040_hdmBusinessIntegrityRules.patch
@@ -28,7 +28,7 @@ diff -Naur xmlmind.orig/addon/config/docbook5/rng/V5.0/docbook.sch xmlmind/addon
 +   </s:pattern>
 +
 +   <s:pattern name="Mandatory Id definition constraint">
-+      <s:rule context="db:chapter|db:section|db:figure|db:equation|db:table|db:qandaset">
++      <s:rule context="db:preface|db:chapter|db:section|db:figure|db:equation|db:table|db:qandaset">
 +         <s:assert test="@xml:id">Each chapter,section, subection,... must have a unique id.</s:assert>
 +      </s:rule>
 +   </s:pattern>