diff --git a/docs/requirements.txt b/docs/requirements.txt
index 10fcd95..1c21633 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,7 +1,7 @@
 # This file is used to setup env
 # to generate documentation.
 
-sphinx==1.7.4
+sphinx==2.1.2
 sphinx-readable-theme==1.3.0
 sphinxcontrib-napoleon==0.6.1
 recommonmark==0.4.0