diff --git a/bind.spec b/bind.spec
index e5c9fd5..d363068 100644
--- a/bind.spec
+++ b/bind.spec
@@ -232,7 +232,9 @@ BuildRequires:  libmaxminddb-devel
 BuildRequires:  fstrm-devel protobuf-c-devel
 %endif
 # Needed to regenerate dig.1 manpage
-BuildRequires:  docbook-style-xsl, libxslt
+# Docbook5 with namespace is required.
+# Visit for details: https://gitlab.isc.org/isc-projects/bind9/-/issues/2310
+BuildRequires:  docbook5-style-xsl, libxslt
 %if %{with TSAN}
 BuildRequires: libtsan
 %endif
@@ -583,6 +585,11 @@ are used for building ISC DHCP.
 mkdir lib/dns/tests/testdata/dstrandom
 cp -a %{SOURCE50} lib/dns/tests/testdata/dstrandom/random.data
 
+# Avoid having [FIXME: manual] on top of generated manual pages
+# https://gitlab.isc.org/isc-projects/bind9/-/merge_requests/4524
+find bin lib/lwres/man -name '*.docbook' -exec \
+  sed -e 's|<refmiscinfo>BIND9|<refmiscinfo class="manual">BIND9|' -i '{}' ';'
+
 %if %{with PKCS11}
 cp -r bin/named{,-pkcs11}
 cp -r bin/dnssec{,-pkcs11}
@@ -727,7 +734,7 @@ export LIBDIR_SUFFIX
   --with-cmocka \
 %endif
   --enable-fixed-rrset \
-  --with-docbook-xsl=%{_datadir}/sgml/docbook/xsl-stylesheets \
+  --with-docbook-xsl=%{_datadir}/sgml/docbook/xsl-ns-stylesheets \
   --enable-full-report \
 ;
 %if %{with DNSTAP}
diff --git a/bind99-rh640538.patch b/bind99-rh640538.patch
index 5066a14..e2c0de7 100644
--- a/bind99-rh640538.patch
+++ b/bind99-rh640538.patch
@@ -1,40 +1,58 @@
+From a76716d5d039947d6fe2cd49a151b16a29e12d42 Mon Sep 17 00:00:00 2001
+From: Petr Mensik <pemensik@redhat.com>
+Date: Mon, 4 Jan 2021 12:55:49 +0100
+Subject: [PATCH] .rh640538
+---
+ bin/dig/dig.docbook | 43 +++++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 43 insertions(+)
+
 diff --git a/bin/dig/dig.docbook b/bin/dig/dig.docbook
-index 1079421..f11abd1 100644
+index 8ccf207..6d16d37 100644
 --- a/bin/dig/dig.docbook
 +++ b/bin/dig/dig.docbook
-@@ -1177,6 +1177,39 @@ dig +qr www.isc.org any -x 127.0.0.1 isc.org ns +noqr
+@@ -1336,6 +1336,49 @@ dig +qr www.isc.org any -x 127.0.0.1 isc.org ns +noqr
      </para>
    </refsection>
  
 +  <refsection><info><title>RETURN CODES</title></info>
++
 +    <para>
 +      <command>Dig</command> return codes are:
++
 +      <variablelist>
-+        <varlistentry>
-+          <listitem>
-+            <para>0: Everything went well, including things like NXDOMAIN</para>
-+          </listitem>
-+        </varlistentry>
-+        <varlistentry>
-+          <listitem>
-+            <para>1: Usage error</para>
-+          </listitem>
-+        </varlistentry>
-+        <varlistentry>
-+          <listitem>
-+            <para>8: Couldn't open batch file</para>
-+          </listitem>
-+        </varlistentry>
-+        <varlistentry>
-+          <listitem>
-+            <para>9: No reply from server</para>
-+          </listitem>
-+        </varlistentry>
-+        <varlistentry>
-+          <listitem>
-+            <para>10: Internal error</para>
-+          </listitem>
-+        </varlistentry>
++	<varlistentry>
++	  <term>0</term>
++	  <listitem>
++	    <para>Everything went well, including things like NXDOMAIN.</para>
++	  </listitem>
++	</varlistentry>
++	<varlistentry>
++	  <term>1</term>
++	  <listitem>
++	    <para>Usage error.</para>
++	  </listitem>
++	</varlistentry>
++
++	<varlistentry>
++	  <term>8</term>
++	  <listitem>
++	    <para>Could not open batch file.</para>
++	  </listitem>
++	</varlistentry>
++	<varlistentry>
++	  <term>9</term>
++	  <listitem>
++	    <para>No reply from server.
++	    </para>
++	  </listitem>
++	</varlistentry>
++	<varlistentry>
++	  <term>10</term>
++	  <listitem>
++	    <para>Internal error.
++	    </para>
++	  </listitem>
++	</varlistentry>
 +      </variablelist>
 +    </para>
 +  </refsection>
@@ -42,3 +60,6 @@ index 1079421..f11abd1 100644
    <refsection><info><title>FILES</title></info>
  
      <para><filename>/etc/resolv.conf</filename>
+-- 
+2.26.2
+