diff --git a/durabletask/task.py b/durabletask/task.py
index 2f49371..3570838 100644
--- a/durabletask/task.py
+++ b/durabletask/task.py
@@ -201,7 +201,7 @@ def lock_entities(self, entities: list[EntityInstanceId]) -> Task[EntityLock]:
         pass
 
     @abstractmethod
-    def call_sub_orchestrator(self, orchestrator: Orchestrator[TInput, TOutput], *,
+    def call_sub_orchestrator(self, orchestrator: Union[Orchestrator[TInput, TOutput], str], *,
                               input: Optional[TInput] = None,
                               instance_id: Optional[str] = None,
                               retry_policy: Optional[RetryPolicy] = None,
diff --git a/durabletask/worker.py b/durabletask/worker.py
index 09f6559..a244927 100644
--- a/durabletask/worker.py
+++ b/durabletask/worker.py
@@ -1029,7 +1029,7 @@ def lock_entities(self, entities: list[EntityInstanceId]) -> task.Task[EntityLoc
 
     def call_sub_orchestrator(
             self,
-            orchestrator: task.Orchestrator[TInput, TOutput],
+            orchestrator: Union[task.Orchestrator[TInput, TOutput], str],
             *,
             input: Optional[TInput] = None,
             instance_id: Optional[str] = None,
@@ -1037,7 +1037,10 @@ def call_sub_orchestrator(
             version: Optional[str] = None,
     ) -> task.Task[TOutput]:
         id = self.next_sequence_number()
-        orchestrator_name = task.get_name(orchestrator)
+        if isinstance(orchestrator, str):
+            orchestrator_name = orchestrator
+        else:
+            orchestrator_name = task.get_name(orchestrator)
         default_version = self._registry.versioning.default_version if self._registry.versioning else None
         orchestrator_version = version if version else default_version
         self.call_activity_function_helper(
diff --git a/tests/durabletask-azuremanaged/test_dts_orchestration_e2e.py b/tests/durabletask-azuremanaged/test_dts_orchestration_e2e.py
index 6155733..1f47810 100644
--- a/tests/durabletask-azuremanaged/test_dts_orchestration_e2e.py
+++ b/tests/durabletask-azuremanaged/test_dts_orchestration_e2e.py
@@ -175,6 +175,34 @@ def parent_orchestrator(ctx: task.OrchestrationContext, count: int):
     assert activity_counter == 30
 
 
+def test_sub_orchestrator_by_name():
+    sub_orchestrator_counter = 0
+
+    def orchestrator_child(ctx: task.OrchestrationContext, _):
+        nonlocal sub_orchestrator_counter
+        sub_orchestrator_counter += 1
+
+    def parent_orchestrator(ctx: task.OrchestrationContext, _):
+        yield ctx.call_sub_orchestrator("orchestrator_child")
+
+    # Start a worker, which will connect to the sidecar in a background thread
+    with DurableTaskSchedulerWorker(host_address=endpoint, secure_channel=True,
+                                    taskhub=taskhub_name, token_credential=None) as w:
+        w.add_orchestrator(orchestrator_child)
+        w.add_orchestrator(parent_orchestrator)
+        w.start()
+
+        task_hub_client = DurableTaskSchedulerClient(host_address=endpoint, secure_channel=True,
+                                                     taskhub=taskhub_name, token_credential=None)
+        id = task_hub_client.schedule_new_orchestration(parent_orchestrator, input=None)
+        state = task_hub_client.wait_for_orchestration_completion(id, timeout=30)
+
+    assert state is not None
+    assert state.runtime_status == client.OrchestrationStatus.COMPLETED
+    assert state.failure_details is None
+    assert sub_orchestrator_counter == 1
+
+
 def test_wait_for_multiple_external_events():
     def orchestrator(ctx: task.OrchestrationContext, _):
         a = yield ctx.wait_for_external_event('A')
diff --git a/tests/durabletask/test_orchestration_e2e.py b/tests/durabletask/test_orchestration_e2e.py
index 63f14c5..6dbc8e1 100644
--- a/tests/durabletask/test_orchestration_e2e.py
+++ b/tests/durabletask/test_orchestration_e2e.py
@@ -162,6 +162,32 @@ def parent_orchestrator(ctx: task.OrchestrationContext, count: int):
     assert activity_counter == 30
 
 
+def test_sub_orchestrator_by_name():
+    sub_orchestrator_counter = 0
+
+    def orchestrator_child(ctx: task.OrchestrationContext, _):
+        nonlocal sub_orchestrator_counter
+        sub_orchestrator_counter += 1
+
+    def parent_orchestrator(ctx: task.OrchestrationContext, _):
+        yield ctx.call_sub_orchestrator("orchestrator_child")
+
+    # Start a worker, which will connect to the sidecar in a background thread
+    with worker.TaskHubGrpcWorker() as w:
+        w.add_orchestrator(orchestrator_child)
+        w.add_orchestrator(parent_orchestrator)
+        w.start()
+
+        task_hub_client = client.TaskHubGrpcClient()
+        id = task_hub_client.schedule_new_orchestration(parent_orchestrator, input=None)
+        state = task_hub_client.wait_for_orchestration_completion(id, timeout=30)
+
+    assert state is not None
+    assert state.runtime_status == client.OrchestrationStatus.COMPLETED
+    assert state.failure_details is None
+    assert sub_orchestrator_counter == 1
+
+
 def test_wait_for_multiple_external_events():
     def orchestrator(ctx: task.OrchestrationContext, _):
         a = yield ctx.wait_for_external_event('A')