diff --git a/xsl/annotation.xsl b/xsl/annotation.xsl
index 16e7620..11d9f54 100644
--- a/xsl/annotation.xsl
+++ b/xsl/annotation.xsl
@@ -8,6 +8,9 @@
   -->
 <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                 version="1.0">
+  <xsl:variable name="uppercase-letters" select="'ABCDEFGHIJKLMNOPQRSTUVWXYZ'"/>
+  <xsl:variable name="lowercase-letters" select="'abcdefghijklmnopqrstuvwxyz'"/>
+
   <xsl:key name="classes" match="class|struct|union|typedef" use="@name"/>
   <xsl:key name="methods" match="method|overloaded-method" use="@name"/>
   <xsl:key name="functions" match="function|overloaded-function" use="@name"/>
@@ -17,7 +20,7 @@
   <xsl:key name="macros" match="macro" use="@name"/>
   <xsl:key name="headers" match="header" use="@name"/>
   <xsl:key name="globals" match="namespace/data-member|header/data-member" use="@name"/>
-  <xsl:key name="named-entities" match="class|struct|union|concept|function|overloaded-function|macro|library|namespace/data-member|header/data-member|*[attribute::id]" use="@name|@id"/>
+  <xsl:key name="named-entities" match="class|struct|union|concept|function|overloaded-function|macro|library|namespace/data-member|header/data-member|*[attribute::id]" use="translate(@name|@id, $uppercase-letters, $lowercase-letters)"/>
 
   <xsl:template match="function|overloaded-function" mode="generate.id">
     <xsl:call-template name="fully-qualified-id">
diff --git a/xsl/lookup.xsl b/xsl/lookup.xsl
index 5a4a34c..1dd362d 100644
--- a/xsl/lookup.xsl
+++ b/xsl/lookup.xsl
@@ -225,7 +225,8 @@
   </xsl:template>
 
   <xsl:template match="function|overloaded-function" mode="unique.name">
-    <xsl:value-of select="number(count(key('named-entities', @name)) = 1)"/>
+    <xsl:value-of select="number(count(key('named-entities',
+        translate(@name, $uppercase-letters, $lowercase-letters))) = 1)"/>
   </xsl:template>
 
   <!-- Print the name of the current node -->
diff --git a/xsl/macro.xsl b/xsl/macro.xsl
index a792eff..e396295 100644
--- a/xsl/macro.xsl
+++ b/xsl/macro.xsl
@@ -74,7 +74,8 @@
 
   <xsl:template match="macro" mode="generate.id">
     <xsl:value-of select="@name"/>
-    <xsl:if test="count(key('named-entities', @name))!=1">
+    <xsl:if test="count(key('named-entities',
+        translate(@name, $uppercase-letters, $lowercase-letters)))!=1">
       <xsl:text>_</xsl:text>
       <xsl:value-of select="generate-id(.)"/>
     </xsl:if>