diff --git a/docs/conf.py b/docs/conf.py
index 73b87e6bf..559e979a3 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -60,4 +60,4 @@
 
 # -- Options for HTML output -------------------------------------------------
 
-html_theme = "classic"
+html_theme = "sphinx_rtd_theme"
diff --git a/pyproject.toml b/pyproject.toml
index 421eb1c9a..4babc60a2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -55,6 +55,7 @@ dev = [
 ]
 doc = [
     "sphinx",
+    "sphinx-rtd-theme",
     "ipykernel",
     "nbsphinx",
     "myst-parser",