diff --git a/docs/environment.yml b/docs/environment.yml
index b35ceb7..e75373e 100644
--- a/docs/environment.yml
+++ b/docs/environment.yml
@@ -2,8 +2,8 @@ name: ipython_docs
 dependencies:
 - python=3.8
 - setuptools>=18.5
-- sphinx>=1.8
-- sphinx_rtd_theme
+- sphinx>=4.2.0
+- sphinx_rtd_theme>=1.0.0
 - numpy
 - testpath
 - matplotlib