diff --git a/build/check_namespaces.xsl b/build/check_namespaces.xsl
index 81e2b4d4..2a3f83f4 100644
--- a/build/check_namespaces.xsl
+++ b/build/check_namespaces.xsl
@@ -24,6 +24,7 @@
 	xmlns:shibmd="urn:mace:shibboleth:metadata:1.0"
 	xmlns:ukfedlabel="http://ukfederation.org.uk/2006/11/label"
 	xmlns:wayf="http://sdss.ac.uk/2006/06/WAYF"
+	xmlns:xenc="http://www.w3.org/2001/04/xmlenc#"
 	
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
@@ -94,6 +95,10 @@
 		<xsl:apply-templates/>
 	</xsl:template>
 	
+	<xsl:template match="xenc:*">
+		<xsl:apply-templates/>
+	</xsl:template>
+	
 	<!--
 		Reject elements in all other namespaces.
 	-->