diff -Nru w3-dtd-mathml-2.0.0.0/debian/catalog.xml w3-dtd-mathml-2.0.0.0/debian/catalog.xml
--- w3-dtd-mathml-2.0.0.0/debian/catalog.xml	2011-06-15 20:48:40.000000000 +0000
+++ w3-dtd-mathml-2.0.0.0/debian/catalog.xml	2012-05-22 07:43:40.000000000 +0000
@@ -17,4 +17,7 @@
   <system systemId="http://www.w3.org/TR/MathML2/dtd/xhtml-math11-f.dtd"
     uri="xhtml-math11-f.dtd"/>
 
+  <rewriteSystem systemIdStartString="http://www.w3.org/TR/MathML2/dtd/"
+    rewritePrefix="./"/>
+
 </catalog>
diff -Nru w3-dtd-mathml-2.0.0.0/debian/changelog w3-dtd-mathml-2.0.0.0/debian/changelog
--- w3-dtd-mathml-2.0.0.0/debian/changelog	2012-05-11 15:23:43.000000000 +0000
+++ w3-dtd-mathml-2.0.0.0/debian/changelog	2012-05-31 07:22:10.000000000 +0000
@@ -1,3 +1,9 @@
+w3-dtd-mathml (2.0.0.0-5) unstable; urgency=low
+
+  * .ent files not taken into account in the catalog system. Closes: #283173
+
+ -- Mathieu Malaterre <malat@debian.org>  Thu, 31 May 2012 09:22:06 +0200
+
 w3-dtd-mathml (2.0.0.0-4) unstable; urgency=low
 
   * Properly install XML catalogs. Closes: #637394