diff --git a/python/docs/_inventory/python-3.10.inv b/python/docs/_inventory/python-3.10.inv
new file mode 100644
index 00000000000..78549c31926
Binary files /dev/null and b/python/docs/_inventory/python-3.10.inv differ
diff --git a/python/docs/conf.py b/python/docs/conf.py
index e836c2b44d5..487d9ea60de 100644
--- a/python/docs/conf.py
+++ b/python/docs/conf.py
@@ -70,6 +70,11 @@
 
 toc_object_entries = False
 
+# Resolve stdlib cross-references against a vendored inventory instead of
+# fetching docs.python.org/3.10/objects.inv at build time. The public URL is
+# still used for the generated links; only the inventory is read locally, so a
+# docs.python.org outage can't break the strict (-W) build. Python 3.10 is
+# frozen, so the file never needs refreshing.
 intersphinx_mapping = {
-    "python": ("https://docs.python.org/3.10", None),
+    "python": ("https://docs.python.org/3.10", "_inventory/python-3.10.inv"),
 }