diff --git a/lib/spack/docs/requirements.txt b/lib/spack/docs/requirements.txt
index 58877fcfc27d87..43dfcaba24365d 100644
--- a/lib/spack/docs/requirements.txt
+++ b/lib/spack/docs/requirements.txt
@@ -1,7 +1,7 @@
 sphinx==7.4.7
 sphinxcontrib-programoutput==0.17
 sphinx_design==0.6.1
-sphinx-rtd-theme==2.0.0
+sphinx-rtd-theme==3.0.0
 python-levenshtein==0.25.1
 docutils==0.21.2
 pygments==2.18.0