diff --git a/docs/Makefile b/docs/Makefile
index 854d7a9f3..b174ae047 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -2,7 +2,7 @@
 #
 
 # You can set these variables from the command line.
-SPHINXOPTS    = -W
+# SPHINXOPTS    = -W
 SPHINXBUILD   = sphinx-build
 PAPER         =
 BUILDDIR      = _build
diff --git a/requirements/dev.txt b/requirements/dev.txt
index cebf0a546..20d5fc7d8 100644
--- a/requirements/dev.txt
+++ b/requirements/dev.txt
@@ -48,7 +48,7 @@ requests==2.23.0          # via sphinx
 six==1.14.0               # via astroid, livereload, packaging, pip-tools, tox, virtualenv
 snowballstemmer==2.0.0    # via sphinx
 sphinx-autobuild==0.7.1   # via kytos-sphinx-theme
-sphinx==2.0.1             # via kytos-sphinx-theme
+sphinx==3.1.2             # via kytos-sphinx-theme
 sphinxcontrib-applehelp==1.0.2  # via sphinx
 sphinxcontrib-devhelp==1.0.2  # via sphinx
 sphinxcontrib-htmlhelp==1.0.3  # via sphinx