diff --git a/setup.py b/setup.py
index 45aab30713..0884e4584c 100644
--- a/setup.py
+++ b/setup.py
@@ -50,7 +50,7 @@
         extras_require['xmlio']
         + extras_require['contrib']
         + [
-            'sphinx>=4.0.0',
+            'sphinx>=4.0.0,!=5.1.0',  # c.f. https://github.com/scikit-hep/pyhf/pull/1925
             'sphinxcontrib-bibtex~=2.1',
             'sphinx-click',
             'sphinx_rtd_theme',