diff --git a/setup.cfg b/setup.cfg
index de188f3..1110016 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -35,6 +35,10 @@ version = 0.20.dev
 [entry_points]
 speclite_benchmark = speclite.benchmark:main
 
+[options.extras_require]
+docs =
+    sphinx-astropy
+
 [tool:pytest]
 testpaths = "speclite" "docs"
 norecursedirs = build docs/_build