diff --git a/doc/changelog.rst b/doc/changelog.rst
index ef96658e7a..6089f6f680 100644
--- a/doc/changelog.rst
+++ b/doc/changelog.rst
@@ -4,6 +4,11 @@ Changelog
 Changes in Version 3.13.0
 -------------------------
 
+Version 3.13 provides an upgrade path to PyMongo 4.x. Most of the API changes
+from PyMongo 4.0 have been backported in a backward compatible way, allowing
+applications to be written against PyMongo >= 3.13, rather then PyMongo 3.x or
+PyMongo 4.x. See the `PyMongo 4 Migration Guide`_ for detailed examples.
+
 Notable improvements
 ....................
 - Added :attr:`pymongo.mongo_client.MongoClient.options` for read-only access
@@ -43,11 +48,11 @@ Deprecations
 - Deprecated :attr:`pymongo.mongo_client.MongoClient.retry_reads`.
   Use :attr:`~pymongo.mongo_client.options.retry_reads` instead.
 - Deprecated :attr:`pymongo.mongo_client.MongoClient.max_bson_size`,
-:attr:`pymongo.mongo_client.MongoClient.max_message_size`, and
-:attr:`pymongo.mongo_client.MongoClient.max_write_batch_size`. These helpers
-were incorrect when in ``loadBalanced=true mode`` and ambiguous in clusters
-with mixed versions. Use the `hello command`_ to get the authoritative
-value from the remote server instead. Code like this::
+  :attr:`pymongo.mongo_client.MongoClient.max_message_size`, and
+  :attr:`pymongo.mongo_client.MongoClient.max_write_batch_size`. These helpers
+  were incorrect when in ``loadBalanced=true mode`` and ambiguous in clusters
+  with mixed versions. Use the `hello command`_ to get the authoritative
+  value from the remote server instead. Code like this::
 
     max_bson_size = client.max_bson_size
     max_message_size = client.max_message_size
@@ -65,6 +70,7 @@ can be changed to this::
 See the `PyMongo 3.13.0 release notes in JIRA`_ for the list of resolved issues
 in this release.
 
+.. _PyMongo 4 Migration Guide: https://pymongo.readthedocs.io/en/stable/migrate-to-pymongo4.html
 .. _PYTHON-3222: https://jira.mongodb.org/browse/PYTHON-3222
 .. _PyMongo 3.13.0 release notes in JIRA: https://jira.mongodb.org/secure/ReleaseNote.jspa?projectId=10004&version=31570
 
diff --git a/pymongo/collection.py b/pymongo/collection.py
index 57d4454002..112a07d0bc 100644
--- a/pymongo/collection.py
+++ b/pymongo/collection.py
@@ -2053,8 +2053,6 @@ def count(self, filter=None, session=None, **kwargs):
 
         .. _$expr: https://docs.mongodb.com/manual/reference/operator/query/expr/
         .. _$geoWithin: https://docs.mongodb.com/manual/reference/operator/query/geoWithin/
-        .. _$center: https://docs.mongodb.com/manual/reference/operator/query/center/#op._S_center
-        .. _$centerSphere: https://docs.mongodb.com/manual/reference/operator/query/centerSphere/#op._S_centerSphere
         """
         warnings.warn(
             "count is deprecated. Use estimated_document_count or "
diff --git a/pymongo/mongo_client.py b/pymongo/mongo_client.py
index 7c00a9ef18..ab1b9831c8 100644
--- a/pymongo/mongo_client.py
+++ b/pymongo/mongo_client.py
@@ -1157,6 +1157,7 @@ def max_pool_size(self):
     def min_pool_size(self):
         """**DEPRECATED**: The minimum required number of concurrent connections that the pool
         will maintain to each connected server. Default is 0.
+
         .. versionchanged:: 3.13
            Deprecated.
         """
diff --git a/setup.py b/setup.py
index 734e47f33b..bdd39279bb 100755
--- a/setup.py
+++ b/setup.py
@@ -200,7 +200,7 @@ def output_difference(self, example, got, optionflags):
             except:
                 pass
 
-        sphinx_args = ["-E", "-b", mode, "doc", path]
+        sphinx_args = ["-E", "-b", mode, "doc", path, "-W"]
 
         # sphinx.main calls sys.exit when sphinx.build_main exists.
         # Call build_main directly so we can check status and print