diff --git a/doc/requirements.txt b/doc/requirements.txt
index 6a29daa..a94eee0 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -1,4 +1,4 @@
-sphinx>=2.0.0,!=2.1.0 # BSD
+sphinx>=2.0.0 # BSD
 openstackdocstheme>=2.2.1 # Apache-2.0
 
 reno>=3.1.0 # Apache-2.0