diff --git a/sphinx_immaterial/apidoc/python/default.py b/sphinx_immaterial/apidoc/python/default.py
index 65041c87d..47d37dd0f 100644
--- a/sphinx_immaterial/apidoc/python/default.py
+++ b/sphinx_immaterial/apidoc/python/default.py
@@ -1,3 +1,4 @@
+import sphinx
 import sphinx.application
 
 from . import annotation_style
@@ -9,11 +10,13 @@
 from . import attribute_style
 from . import napoleon_admonition_classes
 from . import strip_property_prefix
-from . import section_titles
 from . import autodoc_property_type
 from . import type_annotation_transforms
 from . import strip_self_and_return_type_annotations
 
+if sphinx.version_info < (5, 3):
+    from . import section_titles
+
 
 def setup(app: sphinx.application.Sphinx):
     app.setup_extension(parameter_objects.__name__)
diff --git a/sphinx_immaterial/apidoc/python/section_titles.py b/sphinx_immaterial/apidoc/python/section_titles.py
index 59f0de640..5c99ff38b 100644
--- a/sphinx_immaterial/apidoc/python/section_titles.py
+++ b/sphinx_immaterial/apidoc/python/section_titles.py
@@ -1,10 +1,15 @@
 import docutils.nodes
 import docutils.statemachine
 
+import sphinx
 from sphinx.domains.python import PyObject
 import sphinx.util.nodes
 
 
+# Not needed in Sphinx 5.3
+assert sphinx.version_info < (5, 3)
+
+
 def _monkey_patch_python_domain_to_support_titles():
     """Enables support for titles in all Python directive types.