diff --git a/docs/requirements.txt b/docs/requirements.txt
index 4cc701b..3f47374 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,4 +1,4 @@
-sphinx==2.3.0
+sphinx==2.3.1
 sphinx-rtd-theme==0.4.3
 sphinx-fakeinv==1.0.0
 m2r==0.2.1