diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index ac571724..e3f6ebda 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -6,6 +6,8 @@ v3.1.1
 
 *Release date: In development*
 
+- Upgrade Sphinx version from 4.* to 7.* to fix readthedocs theme format
+
 v3.1.0
 ------
 
diff --git a/docs/requirements.txt b/docs/requirements.txt
index f3415ccf..77b8ac80 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,3 +1,3 @@
-Sphinx==4.*
-sphinx_rtd_theme==1.*
-readthedocs-sphinx-search==0.1.*
+Sphinx~=7.2
+sphinx_rtd_theme~=1.3
+readthedocs-sphinx-search~=0.3