diff --git a/docs/UsersGuide/requirements.txt b/docs/UsersGuide/requirements.txt
index edcb382114..7be32f526d 100644
--- a/docs/UsersGuide/requirements.txt
+++ b/docs/UsersGuide/requirements.txt
@@ -1,2 +1,3 @@
 sphinxcontrib-bibtex
-sphinx_rtd_theme
\ No newline at end of file
+sphinx_rtd_theme
+docutils==0.16
\ No newline at end of file
diff --git a/docs/UsersGuide/source/conf.py b/docs/UsersGuide/source/conf.py
index 1d2ca24325..1490321e96 100644
--- a/docs/UsersGuide/source/conf.py
+++ b/docs/UsersGuide/source/conf.py
@@ -41,6 +41,7 @@
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
 extensions = [
+    'sphinx_rtd_theme',
     'sphinx.ext.autodoc',
     'sphinx.ext.doctest',
     'sphinx.ext.intersphinx',