diff --git a/setup.cfg b/setup.cfg
index 947f8aa8..94f7354b 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -62,8 +62,6 @@ rtd =
     sphinx-book-theme~=0.1.0
     sphinx-panels~=0.5.2
     sphinxcontrib-bibtex~=2.1
-# left in for back-compatability
-sphinx =
 testing =
     beautifulsoup4
     coverage