diff --git a/langfuse/decorators/langfuse_decorator.py b/langfuse/decorators/langfuse_decorator.py
index 984cd5b32..137ba84b7 100644
--- a/langfuse/decorators/langfuse_decorator.py
+++ b/langfuse/decorators/langfuse_decorator.py
@@ -364,7 +364,9 @@ def _prepare_call(
                 # Create wrapper trace if generation is top-level
                 # Do not add wrapper trace to stack, as it does not have a corresponding end that will pop it off again
                 trace = self.client_instance.trace(
-                    id=id, name=name, start_time=start_time
+                    id=_root_trace_id_context.get() or id,
+                    name=name,
+                    start_time=start_time,
                 )
                 self._set_root_trace_id(trace.id)
 
diff --git a/tests/test_singleton.py b/tests/test_singleton.py
index cf77c4b1d..c54c86f79 100644
--- a/tests/test_singleton.py
+++ b/tests/test_singleton.py
@@ -1,6 +1,8 @@
-import pytest
 import threading
 from unittest.mock import patch
+
+import pytest
+
 from langfuse.utils.langfuse_singleton import LangfuseSingleton
 
 
@@ -64,4 +66,4 @@ def test_reset_functionality(mock_langfuse):
 
     assert instance._langfuse is None
 
-    mock_langfuse.return_value.flush.assert_called_once()
+    mock_langfuse.return_value.shutdown.assert_called_once()