diff --git a/{{cookiecutter.project_name}}/.readthedocs.yaml b/{{cookiecutter.project_name}}/.readthedocs.yaml
index 6c284771..bd0b1f5b 100644
--- a/{{cookiecutter.project_name}}/.readthedocs.yaml
+++ b/{{cookiecutter.project_name}}/.readthedocs.yaml
@@ -3,7 +3,7 @@ version: 2
 build:
   os: ubuntu-24.04
   tools:
-    python: "3.13"
+    python: "3.14"
     nodejs: latest
   jobs:
     create_environment:
diff --git a/{{cookiecutter.project_name}}/docs/conf.py b/{{cookiecutter.project_name}}/docs/conf.py
index 010d30f0..12bc28cc 100644
--- a/{{cookiecutter.project_name}}/docs/conf.py
+++ b/{{cookiecutter.project_name}}/docs/conf.py
@@ -87,6 +87,7 @@
 nb_execution_mode = "off"
 nb_merge_streams = True
 typehints_defaults = "braces"
+always_use_bars_union = True  # use `|` instead of `Union` in types even when building with Python ≤3.14
 
 source_suffix = {
     ".rst": "restructuredtext",
@@ -95,8 +96,7 @@
 }
 
 intersphinx_mapping = {
-    # TODO: replace `3.13` with `3` once ReadTheDocs supports building with Python 3.14
-    "python": ("https://docs.python.org/3.13", None),
+    "python": ("https://docs.python.org/3", None),
     "anndata": ("https://anndata.readthedocs.io/en/stable/", None),
     "scanpy": ("https://scanpy.readthedocs.io/en/stable/", None),
     "numpy": ("https://numpy.org/doc/stable/", None),