diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5d2b6c39a..c2f896219 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,10 @@ Changes are grouped as follows
 - `Fixed` for any bug fixes.
 - `Security` in case of vulnerabilities.
 
+## [7.64.5] - 2024-11-01
+### Fixed
+- The `client.functions.schedules.create` method no longer mutates the input `FunctionScheduleWrite` object.
+
 ## [7.64.4] - 2024-11-01
 ### Fixed
 - Data Workflows: apply more robust path parameter encoding.
diff --git a/cognite/client/_api/functions.py b/cognite/client/_api/functions.py
index d1d4a4b10..24dbc2d35 100644
--- a/cognite/client/_api/functions.py
+++ b/cognite/client/_api/functions.py
@@ -1284,7 +1284,8 @@ def create(
                 raise ValueError("cron_expression must be specified when creating a new schedule.")
             item = FunctionScheduleWrite(name, cron_expression, function_id, function_external_id, description, data)
         else:
-            item = name
+            # We serialize the object as we mutate `item` using the result from _get_function_internal_id.
+            item = FunctionScheduleWrite._load(name.dump())
         identifier = _get_function_identifier(item.function_id, item.function_external_id)
         if item.function_id is None:
             item.function_id = _get_function_internal_id(self._cognite_client, identifier)
diff --git a/cognite/client/_version.py b/cognite/client/_version.py
index d6047efe9..38b06ea1f 100644
--- a/cognite/client/_version.py
+++ b/cognite/client/_version.py
@@ -1,4 +1,4 @@
 from __future__ import annotations
 
-__version__ = "7.64.4"
+__version__ = "7.64.5"
 __api_subversion__ = "20230101"
diff --git a/pyproject.toml b/pyproject.toml
index 07a58aa2d..43da3b218 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 [tool.poetry]
 name = "cognite-sdk"
 
-version = "7.64.4"
+version = "7.64.5"
 description = "Cognite Python SDK"
 readme = "README.md"
 documentation = "https://cognite-sdk-python.readthedocs-hosted.com"
diff --git a/tests/tests_integration/test_api/test_functions.py b/tests/tests_integration/test_api/test_functions.py
index d3c456f6d..d073cf566 100644
--- a/tests/tests_integration/test_api/test_functions.py
+++ b/tests/tests_integration/test_api/test_functions.py
@@ -92,12 +92,20 @@ def test_create_retrieve_delete(self, cognite_client: CogniteClient, a_function:
             function_external_id=a_function.external_id,
             data={"key": "value"},
         )
+        original_schedule = FunctionScheduleWrite._load(my_schedule.dump())
 
         created: FunctionSchedule | None = None
         try:
             created = cognite_client.functions.schedules.create(my_schedule)
 
-            assert created.as_write().dump() == my_schedule.dump()
+            created_dump = created.as_write().dump()
+            created_dump.pop("functionId")
+            my_dump = my_schedule.dump()
+            my_dump.pop("functionExternalId")
+
+            assert created_dump == my_dump
+            # This check is to ensure that the original schedule is not modified
+            assert my_schedule.dump() == original_schedule.dump()
 
             retrieved = cognite_client.functions.schedules.retrieve(id=created.id)
             assert isinstance(retrieved, FunctionSchedule)