diff --git a/resources/templates/fb2.xsl b/resources/templates/fb2.xsl
index 83bb9c7f10..e34fe013cd 100644
--- a/resources/templates/fb2.xsl
+++ b/resources/templates/fb2.xsl
@@ -1,4 +1,4 @@
-<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:fb="http://www.gribuser.ru/xml/fictionbook/2.0">
+<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:fb="__FB_NS__">
 <!--
 #########################################################################
 #                                                                       #
diff --git a/src/calibre/ebooks/conversion/plugins/fb2_input.py b/src/calibre/ebooks/conversion/plugins/fb2_input.py
index 784b13cfc8..6148abd783 100644
--- a/src/calibre/ebooks/conversion/plugins/fb2_input.py
+++ b/src/calibre/ebooks/conversion/plugins/fb2_input.py
@@ -58,6 +58,10 @@ class FB2Input(InputFormatPlugin):
                         parser=RECOVER_PARSER)
         if doc is None:
             raise ValueError('The FB2 file is not valid XML')
+        try:
+            fb_ns = doc.nsmap[doc.prefix]
+        except Exception:
+            fb_ns = 'http://www.gribuser.ru/xml/fictionbook/2.0'
         stylesheets = doc.xpath('//*[local-name() = "stylesheet" and @type="text/css"]')
         css = ''
         for s in stylesheets:
@@ -78,6 +82,7 @@ class FB2Input(InputFormatPlugin):
         self.extract_embedded_content(doc)
         log.debug('Converting XML to HTML...')
         ss = open(P('templates/fb2.xsl'), 'rb').read()
+        ss = ss.replace("__FB_NS__", fb_ns)
         if options.no_inline_fb2_toc:
             log('Disabling generation of inline FB2 TOC')
             ss = re.compile(r'<!-- BUILD TOC -->.*<!-- END BUILD TOC -->',