diff --git a/INSTALL b/INSTALL
index d2902c7..c8c8a8a 100644
--- a/INSTALL
+++ b/INSTALL
@@ -6,7 +6,7 @@
 
 * <<RubyGems>> 1.3.6 or newer.
 
-* <<AsciiDoc>> 8.5.3 or newer.
+* <<AsciiDoc>> 8.6.5 or newer.
 
 * <<Pygments>> 1.3.1 or newer.
 
diff --git a/lib/inochi/tasks/2-man.css b/lib/inochi/tasks/2-man.css
index df76447..257ee96 100644
--- a/lib/inochi/tasks/2-man.css
+++ b/lib/inochi/tasks/2-man.css
@@ -26,18 +26,6 @@
     text-decoration: underline;
   }
 
-  #toc {
-    position: fixed;
-    top: 0;
-    left: 0;
-    bottom: 0;
-    width: 13em;
-    padding: 0.5em;
-    padding-bottom: 1.5em;
-    margin: 0 !important;
-    overflow: auto;
-  }
-
   #toc a {
     color: #083194 !important;
   }
@@ -45,11 +33,6 @@
   #toc .toclevel1 {
     margin-top: 1.25em;
   }
-
-  #toc .toclevel2 {
-    margin-top: 0.25em;
-    display: list-item;
-  }
 }
 
 @media print {
diff --git a/lib/inochi/tasks/2-man.rake b/lib/inochi/tasks/2-man.rake
index 341ca94..611fd01 100644
--- a/lib/inochi/tasks/2-man.rake
+++ b/lib/inochi/tasks/2-man.rake
@@ -41,7 +41,7 @@ CLEAN.include @man_asciidoc_dst
 
 #-----------------------------------------------------------------------------
 
-build_asciidoc_args = proc do |*atts|
+build_asciidoc_attributes = proc do |*atts|
   atts.concat Array(@project_config[:man_asciidoc_attributes])
   args = atts.map {|a| ['-a', a] }.flatten
 
@@ -52,19 +52,19 @@ build_asciidoc_args = proc do |*atts|
 end
 
 file @man_html_dst => @man_asciidoc_dst do
-  args = build_asciidoc_args.call(
+  args = build_asciidoc_attributes.call(
     'pygments', # for better syntax coloring than GNU Source Highlight
     'data-uri', # to ensure the output is a monolithic HTML document
     'icons', 'iconsdir={asciidoc-confdir}/{iconsdir}',
-    'toc', 'stylesheet=' + __FILE__.ext('css')
+    'toc2', 'stylesheet=' + __FILE__.ext('css')
   )
-  sh 'asciidoc', '-o', @man_html_dst, *args
+  sh 'asciidoc', '-o', @man_html_dst, '-b', 'html5', *args
 end
 
 CLOBBER.include @man_html_dst
 
 file @man_docbook_dst => @man_asciidoc_dst do
-  args = build_asciidoc_args.call
+  args = build_asciidoc_attributes.call
   mkdir_p File.dirname(@man_docbook_dst)
   sh 'asciidoc', '-o', @man_docbook_dst, '-d', 'manpage', '-b', 'docbook', *args
 end