diff --git a/requirements.txt b/requirements.txt
index 1d18dd3..5c8b4f0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 # The order of packages is significant, because pip processes them in the order
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
-
-pbr>=2.0 # Apache-2.0
+otcdocstheme # Apache-2.0
+sphinx>=2.0.0,!=2.1.0 # BSD