diff --git a/src/firebase_functions/options.py b/src/firebase_functions/options.py
index ee084cbe..cf327889 100644
--- a/src/firebase_functions/options.py
+++ b/src/firebase_functions/options.py
@@ -869,6 +869,7 @@ def _endpoint(
                 schedule=self.schedule,
                 timeZone=time_zone,
                 retryConfig=retry_config,
+                attemptDeadlineSeconds=self.timeout_sec,
             ),
         }
         return _manifest.ManifestEndpoint(**_typing.cast(dict, kwargs_merged))
diff --git a/src/firebase_functions/private/manifest.py b/src/firebase_functions/private/manifest.py
index 7672a9f5..7a9a9c13 100644
--- a/src/firebase_functions/private/manifest.py
+++ b/src/firebase_functions/private/manifest.py
@@ -125,6 +125,7 @@ class ScheduleTrigger(_typing.TypedDict):
     schedule: str | _params.Expression[str]
     timeZone: str | _params.Expression[str] | _util.Sentinel | None
     retryConfig: RetryConfigScheduler | None
+    attemptDeadlineSeconds: int | _params.Expression[int] | _util.Sentinel | None
 
 
 class BlockingTriggerOptions(_typing.TypedDict):
diff --git a/tests/test_scheduler_fn.py b/tests/test_scheduler_fn.py
index f3ad92f1..8c7dc5c00 100644
--- a/tests/test_scheduler_fn.py
+++ b/tests/test_scheduler_fn.py
@@ -47,6 +47,18 @@ def test_on_schedule_decorator(self):
         self.assertEqual(endpoint.scheduleTrigger.get("schedule"), schedule)
         self.assertEqual(endpoint.scheduleTrigger.get("timeZone"), tz)
 
+    def test_on_schedule_with_timeout(self):
+        """
+        Tests that attemptDeadlineSeconds is set to timeoutSeconds.
+        """
+        decorated_func = scheduler_fn.on_schedule(
+            schedule="* * * * *",
+            timeout_sec=120,
+        )(Mock(__name__="example_func"))
+        endpoint = decorated_func.__firebase_endpoint__
+        self.assertEqual(endpoint.timeoutSeconds, 120)
+        self.assertEqual(endpoint.scheduleTrigger.get("attemptDeadlineSeconds"), 120)
+
     def test_on_schedule_call(self):
         """
         Tests to ensure the decorated function is called correctly