diff --git a/setup.py b/setup.py
index 8d1fe855c..a05007c3d 100644
--- a/setup.py
+++ b/setup.py
@@ -17,7 +17,7 @@
  render `Doxygen <http://www.doxygen.org>`__ xml output.
 """
 
-requires = ["Sphinx>=3.0,<5", "docutils>=0.12"]
+requires = ["Sphinx>=4.0,<6,!=5.0.0", "docutils>=0.12"]
 
 if sys.version_info < (3, 6):
     print("ERROR: Sphinx requires at least Python 3.6 to run.")