diff --git a/litellm/integrations/langfuse/langfuse_otel.py b/litellm/integrations/langfuse/langfuse_otel.py
index 342b8ef5148..69d03fdcdd5 100644
--- a/litellm/integrations/langfuse/langfuse_otel.py
+++ b/litellm/integrations/langfuse/langfuse_otel.py
@@ -1,6 +1,7 @@
 import base64
 import json
 import os
+from collections.abc import Mapping
 from datetime import datetime
 from typing import TYPE_CHECKING, Any, Final, Optional
 
@@ -42,7 +43,7 @@ class LangfuseOtelLogger(OpenTelemetry):
         super().__init__(config=config, *args, **kwargs)
 
     @staticmethod
-    def set_langfuse_otel_attributes(span: Span, kwargs: dict[str, object], response_obj) -> None:
+    def set_langfuse_otel_attributes(span: Span, kwargs, response_obj) -> None:
         """
         Sets OpenTelemetry span attributes for Langfuse observability.
         Uses the same attribute setting logic as Arize Phoenix for consistency.
@@ -55,7 +56,13 @@ class LangfuseOtelLogger(OpenTelemetry):
         # Set Langfuse specific attributes
         #########################################################
         LangfuseOtelLogger._set_langfuse_specific_attributes(span=span, kwargs=kwargs, response_obj=response_obj)
-        LangfuseOtelLogger._set_trace_user_attribute(span=span, kwargs=kwargs)
+        LangfuseOtelLogger._set_trace_user_attribute(
+            span=span,
+            kwargs=kwargs,
+            metadata=as_str_mapping(
+                LangfuseOtelLogger._extract_langfuse_metadata(kwargs)  # pyright: ignore[reportUnknownArgumentType,reportUnknownMemberType]  # helper returns a loosely typed dict
+            ),
+        )
 
     @staticmethod
     def _extract_langfuse_metadata(kwargs: dict) -> dict:
@@ -260,14 +267,13 @@ class LangfuseOtelLogger(OpenTelemetry):
         LangfuseOtelLogger._set_observation_output(span=span, response_obj=response_obj)
 
     @staticmethod
-    def _set_trace_user_attribute(span: Span, kwargs: dict[str, object]) -> None:
+    def _set_trace_user_attribute(
+        span: Span, kwargs: Mapping[str, object], metadata: Mapping[str, object] | None
+    ) -> None:
         slp: Final = as_str_mapping(kwargs.get("standard_logging_object"))
         slp_metadata: Final = as_str_mapping(slp.get("metadata")) if slp is not None else None
         if slp is None or slp_metadata is None:
             return
-        metadata: Final = as_str_mapping(
-            LangfuseOtelLogger._extract_langfuse_metadata(kwargs)  # pyright: ignore[reportUnknownArgumentType,reportUnknownMemberType]  # helper returns a loosely typed dict
-        )
         litellm_params: Final = as_str_mapping(kwargs.get("litellm_params")) or {}
         bodies: Final = metadata_bodies(litellm_params)
         caller: Final = (as_str(metadata.get("trace_user_id")) if metadata is not None else None) or next(
@@ -279,7 +285,7 @@ class LangfuseOtelLogger(OpenTelemetry):
         end_user: Final = (
             slp_metadata.get("user_api_key_end_user_id")
             or slp.get("end_user")
-            or next((value for body in bodies if (value := as_str(body.get("user_api_key_end_user_id")))), None)
+            or next((found for body in bodies if (found := as_str(body.get("user_api_key_end_user_id")))), None)
         )
         if end_user:
             safe_set_attribute(span, LangfuseSpanAttributes.TRACE_USER_ID.value, str(end_user))
diff --git a/tests/integration/observability/test_langfuse_otel_identity_chaos.py b/tests/integration/observability/test_langfuse_otel_identity_chaos.py
index 4a627ea7e73..24125cd0410 100644
--- a/tests/integration/observability/test_langfuse_otel_identity_chaos.py
+++ b/tests/integration/observability/test_langfuse_otel_identity_chaos.py
@@ -1,6 +1,4 @@
 import concurrent.futures
-import os
-import signal
 import threading
 import time
 import uuid
@@ -19,7 +17,7 @@ from _langfuse_otel import (
     _upstream_reply_for,
 )
 from integration._support.client import Gateway, eventually
-from integration._support.process import group_members, owned_proxy_process
+from integration._support.process import owned_proxy_process
 from integration._support.wire import Reply, Request, Wire, wire_server
 
 
@@ -208,11 +206,9 @@ def test_langfuse_otel_worker_kill_mid_burst_keeps_every_marker(gateway: Gateway
             for future in concurrent.futures.as_completed(futures):
                 results[futures[future]] = future.result()
                 if len(results) >= 10 and not killed["done"]:
-                    children: Final = tuple(
-                        process for process in group_members(owned.process.pid) if process.pid != owned.process.pid
-                    )
-                    assert children, "no uvicorn worker child found"
-                    os.kill(children[0].pid, signal.SIGKILL)
+                    serving: Final = owned.worker_pids()
+                    assert serving, "no uvicorn worker child found"
+                    owned.kill_worker(min(serving))
                     killed["done"] = True
         assert killed["done"], "worker kill never fired"
         accepted: Final = {m for m, r in results.items() if r["status"] == 200}