diff --git a/lib/spack/docs/requirements.txt b/lib/spack/docs/requirements.txt
index cb766413d951c3..b23248a9266172 100644
--- a/lib/spack/docs/requirements.txt
+++ b/lib/spack/docs/requirements.txt
@@ -1,4 +1,4 @@
-sphinx==7.4.7
+sphinx==8.1.3
 sphinxcontrib-programoutput==0.17
 sphinx_design==0.6.1
 sphinx-rtd-theme==2.0.0