diff --git a/xmlsort.xsl b/xmlsort.xsl
index 6974f45..c15bcaf 100644
--- a/xmlsort.xsl
+++ b/xmlsort.xsl
@@ -4,14 +4,15 @@
   <xsl:output method="xml" indent="yes"/>
   <xsl:strip-space elements="*"/>
 
+
   <xsl:template match="/">
     <xsl:apply-templates/>
   </xsl:template>
 
   <xsl:template match="*">
     <xsl:copy>
-      <!-- Sort the attributes by name. -->
-      <xsl:for-each select="@*">
+      <!-- Sort the attributes by name and remove the xml:base attribute -->
+      <xsl:for-each select="@*[name()!='xml:base']">
         <xsl:sort select="name( . )"/>
         <xsl:copy/>
       </xsl:for-each>
@@ -19,6 +20,19 @@
     </xsl:copy>
   </xsl:template>
 
+  <!-- Remove duplicate model nodes -->
+  <xsl:key name="model-by-name" match="model" use="@name" />
+  <xsl:template match="models">
+    <models>
+      <xsl:for-each select="model[count(. | key('model-by-name', @name)[1]) = 1]">
+        <xsl:copy>
+          <xsl:attribute name="name"><xsl:value-of select="@name"/></xsl:attribute>
+          <xsl:apply-templates/>
+        </xsl:copy>
+      </xsl:for-each>
+    </models>
+  </xsl:template>
+
   <xsl:template match="text()|comment()|processing-instruction()">
     <xsl:copy/>
   </xsl:template>