diff --git a/doc/changelog.rst b/doc/changelog.rst
index a48202e19..f38709203 100644
--- a/doc/changelog.rst
+++ b/doc/changelog.rst
@@ -6,15 +6,6 @@ Changes in Version 4.17.0 (2026/XX/XX)
 
 PyMongo 4.17 brings a number of changes including:
 
-- Remove unused validation functions from pymongo/common.py
-
-  - validate_positive_integer_or_none (line 236) — superseded by
-    validate_non_negative_integer_or_none which is used
-  - validate_int_or_basestring (line 264) — a variant of
-    validate_non_negative_int_or_basestring which is used
-  - validate_auth_option (line 823) — validates auth mechanism properties but
-    is never invoked
-
 - Added the :meth:`~pymongo.asynchronous.client_session.AsyncClientSession.bind` and :meth:`~pymongo.client_session.ClientSession.bind` methods
   that allow users to bind a session to all database operations within the scope of a context manager instead of having to explicitly pass the session to each individual operation.
   See <PLACEHOLDER> for examples and more information.
diff --git a/pymongo/common.py b/pymongo/common.py
index cc53cc65e..118cca89d 100644
--- a/pymongo/common.py
+++ b/pymongo/common.py
@@ -796,8 +796,6 @@ TIMEOUT_OPTIONS: list[str] = [
     "waitqueuetimeoutms",
 ]
 
-_AUTH_OPTIONS = frozenset(["authmechanismproperties"])
-
 
 def _get_validator(
     key: str, validators: dict[str, Callable[[Any, Any], Any]], normed_key: Optional[str] = None