diff --git a/xsl/html-base.xsl b/xsl/html-base.xsl
index 90880b1..a103171 100644
--- a/xsl/html-base.xsl
+++ b/xsl/html-base.xsl
@@ -54,7 +54,7 @@
   <xsl:param name="generate.section.toc.level" select="3"/>
   <xsl:param name="doc.standalone">false</xsl:param>
   <xsl:param name="chunker.output.indent">yes</xsl:param>
-  <xsl:param name="chunker.output.encoding">US-ASCII</xsl:param>
+  <xsl:param name="chunker.output.encoding">UTF-8</xsl:param>
   <xsl:param name="chunk.quietly" select="not(number($boostbook.verbose))"/>
   <xsl:param name="toc.max.depth">2</xsl:param>
   <xsl:param name="callout.graphics.number.limit">15</xsl:param>
diff --git a/xsl/html-single.xsl b/xsl/html-single.xsl
index 6291f25..57547aa 100644
--- a/xsl/html-single.xsl
+++ b/xsl/html-single.xsl
@@ -16,7 +16,7 @@
   <xsl:import
     href="http://docbook.sourceforge.net/release/xsl/current/html/math.xsl"/>
 
-  <xsl:output method="html" encoding="US-ASCII" indent="no"/>
+  <xsl:output method="html" encoding="UTF-8" indent="no"/>
   
   <!-- We have to make sure that our templates override all
        docbook templates.  Therefore, we include our own templates