diff --git a/xsl/html.xsl b/xsl/html.xsl
index 02ed0c1..70c6f40 100644
--- a/xsl/html.xsl
+++ b/xsl/html.xsl
@@ -26,7 +26,7 @@
 
   <xsl:param name="admon.style"/>
   <xsl:param name="admon.graphics">1</xsl:param>
-  <xsl:param name="boostbook.verbose">0</xsl:param>
+  <xsl:param name="boostbook.verbose" select="0"/>
   <xsl:param name="html.stylesheet" select="'boostbook.css'"/>
   <xsl:param name="navig.graphics" select="1"/>
   <xsl:param name="navig.graphics.extension" select="'.png'"/>
@@ -39,7 +39,7 @@
   <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="chunk.quietly" select="not($boostbook.verbose)"/>
+  <xsl:param name="chunk.quietly" select="not(number($boostbook.verbose))"/>
   <xsl:param name="toc.max.depth">2</xsl:param>
   <xsl:param name="callout.graphics.number.limit">15</xsl:param>
   <xsl:param name = "admon.graphics.path"
diff --git a/xsl/xhtml.xsl b/xsl/xhtml.xsl
index dbc1482..bd2a264 100644
--- a/xsl/xhtml.xsl
+++ b/xsl/xhtml.xsl
@@ -26,7 +26,7 @@
 
   <xsl:param name="admon.style"/>
   <xsl:param name="admon.graphics">1</xsl:param>
-  <xsl:param name="boostbook.verbose">0</xsl:param>
+  <xsl:param name="boostbook.verbose" select="0"/>
   <xsl:param name="html.stylesheet" select="'boostbook.css'"/>
   <xsl:param name="navig.graphics" select="1"/>
   <xsl:param name="navig.graphics.extension" select="'.png'"/>
@@ -39,7 +39,7 @@
   <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="chunk.quietly" select="not($boostbook.verbose)"/>
+  <xsl:param name="chunk.quietly" select="not(number($boostbook.verbose))"/>
   <xsl:param name="toc.max.depth">2</xsl:param>
   <xsl:param name="callout.graphics.number.limit">15</xsl:param>
   <xsl:param name = "admon.graphics.path"