diff --git a/api-ref/source/conf.py b/api-ref/source/conf.py
index 023ac19c1..0bd81ddfe 100644
--- a/api-ref/source/conf.py
+++ b/api-ref/source/conf.py
@@ -23,9 +23,7 @@
 # serve to show the default.
 
 import os
-import subprocess
 import sys
-import warnings
 
 import openstackdocstheme
 
@@ -63,19 +61,8 @@ source_suffix = '.rst'
 master_doc = 'index'
 
 # General information about the project.
-project = u'NFV Orchestration API Reference'
 copyright = u'2016-present, OpenStack Foundation'
 
-# The version info for the project you're documenting, acts as replacement for
-# |version| and |release|, also used in various other places throughout the
-# built documents.
-#
-from tacker.version import version_info
-# The full version, including alpha/beta/rc tags.
-release = version_info.release_string()
-# The short X.Y version.
-version = version_info.version_string()
-
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
 #
@@ -147,17 +134,6 @@ pygments_style = 'sphinx'
 # so a file named "default.css" will overwrite the builtin "default.css".
 # html_static_path = ['_static']
 
-# If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
-# using the given strftime format.
-# html_last_updated_fmt = '%b %d, %Y'
-git_cmd = ["git", "log", "--pretty=format:'%ad, commit %h'", "--date=local",
-           "-n1"]
-try:
-    html_last_updated_fmt = subprocess.check_output(git_cmd).decode('utf-8')
-except Exception:
-    warnings.warn('Cannot get last updated time from git repository. '
-                  'Not setting "html_last_updated_fmt".')
-
 # If true, SmartyPants will be used to convert quotes and dashes to
 # typographically correct entities.
 # html_use_smartypants = True
diff --git a/doc/requirements.txt b/doc/requirements.txt
index 9ba4927e1..bf6df613f 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -4,6 +4,6 @@
 sphinx!=1.6.6,!=1.6.7,>=1.6.2,<2.0.0;python_version=='2.7' # BSD
 sphinx!=1.6.6,!=1.6.7,>=1.6.2;python_version>='3.4'  # BSD
 sphinxcontrib-apidoc>=0.2.0  # BSD
-openstackdocstheme>=1.18.1 # Apache-2.0
+openstackdocstheme>=1.20.0 # Apache-2.0
 os-api-ref>=1.4.0 # Apache-2.0
 reno>=2.5.0 # Apache-2.0
diff --git a/doc/source/conf.py b/doc/source/conf.py
index c500d7fc0..2c2b04154 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -77,11 +77,6 @@ htmlhelp_basename = '%sdoc' % project
 # robots.txt.
 html_extra_path = ['_extra']
 
-# If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
-# using the given strftime format.
-# html_last_updated_fmt = '%b %d, %Y'
-html_last_updated_fmt = '%Y-%m-%d %H:%M'
-
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, documentclass
 # [howto/manual]).
diff --git a/lower-constraints.txt b/lower-constraints.txt
index 2558fe197..90dc4ba04 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -62,7 +62,7 @@ munch==2.2.0
 netaddr==0.7.18
 netifaces==0.10.6
 oauthlib==2.0.7
-openstackdocstheme==1.18.1
+openstackdocstheme==1.20.0
 openstacksdk==0.12.0
 os-api-ref==1.5.0
 os-client-config==1.29.0
diff --git a/releasenotes/source/conf.py b/releasenotes/source/conf.py
index 3a2d7251a..4d52867c6 100644
--- a/releasenotes/source/conf.py
+++ b/releasenotes/source/conf.py
@@ -53,7 +53,6 @@ source_suffix = '.rst'
 master_doc = 'index'
 
 # General information about the project.
-project = u'Tacker Release Notes'
 copyright = u'2016, Tacker Developers'
 
 # Release do not need a version number in the title, they
@@ -179,17 +178,6 @@ htmlhelp_basename = 'tackerdoc'
 
 # -- Options for LaTeX output ------------------------------------------------
 
-latex_elements = {
-    # The paper size ('letterpaper' or 'a4paper').
-    # 'papersize': 'letterpaper',
-
-    # The font size ('10pt', '11pt' or '12pt').
-    # 'pointsize': '10pt',
-
-    # Additional stuff for the LaTeX preamble.
-    # 'preamble': '',
-}
-
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, documentclass
 #  [howto/manual]).
diff --git a/requirements.txt b/requirements.txt
index 395e2d221..5a01d5c54 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -35,7 +35,7 @@ oslo.service!=1.28.1,>=1.24.0 # Apache-2.0
 oslo.upgradecheck>=0.1.0 # Apache-2.0
 oslo.utils>=3.33.0 # Apache-2.0
 oslo.versionedobjects>=1.33.3 # Apache-2.0
-openstackdocstheme>=1.18.1 # Apache-2.0
+openstackdocstheme>=1.20.0 # Apache-2.0
 python-neutronclient>=6.7.0 # Apache-2.0
 python-novaclient>=9.1.0 # Apache-2.0
 tosca-parser>=0.8.1 # Apache-2.0