diff --git a/src/crewai/evaluation/evaluation_listener.py b/src/crewai/evaluation/evaluation_listener.py
index 7da1c65a8..8fba03e14 100644
--- a/src/crewai/evaluation/evaluation_listener.py
+++ b/src/crewai/evaluation/evaluation_listener.py
@@ -1,5 +1,5 @@
 from datetime import datetime
-from typing import Any, Dict, List, Optional, Union
+from typing import Any, Dict, Optional
 
 from collections.abc import Sequence
 
@@ -149,7 +149,7 @@ class EvaluationTraceCallback(BaseEventListener):
             "end_time": None
         }
 
-    def on_llm_call_end(self, messages: Union[str, List[Dict[str, Any]]], response: Any):
+    def on_llm_call_end(self, messages: str | list[dict[str, Any]] | None, response: Any):
         if not self.current_agent_id or not self.current_task_id:
             return
 
diff --git a/src/crewai/llm.py b/src/crewai/llm.py
index aa4a8a4ce..d6f40a09a 100644
--- a/src/crewai/llm.py
+++ b/src/crewai/llm.py
@@ -508,7 +508,6 @@ class LLM(BaseLLM):
                             # Enable tool calls using streaming
                             if "tool_calls" in delta:
                                 tool_calls = delta["tool_calls"]
-
                                 if tool_calls:
                                     result = self._handle_streaming_tool_calls(
                                         tool_calls=tool_calls,
@@ -517,6 +516,7 @@ class LLM(BaseLLM):
                                         from_task=from_task,
                                         from_agent=from_agent,
                                     )
+
                                     if result is not None:
                                         chunk_content = result
 
@@ -861,6 +861,7 @@ class LLM(BaseLLM):
                         tool_args=function_args,
                     ),
                 )
+
                 result = fn(**function_args)
                 crewai_event_bus.emit(
                     self,
@@ -991,7 +992,7 @@ class LLM(BaseLLM):
                 logging.error(f"LiteLLM call failed: {str(e)}")
                 raise
 
-    def _handle_emit_call_events(self, response: Any, call_type: LLMCallType, from_task: Optional[Any] = None, from_agent: Optional[Any] = None, messages: Optional[Union[str, List[Dict[str, Any]]]] = None):
+    def _handle_emit_call_events(self, response: Any, call_type: LLMCallType, from_task: Optional[Any] = None, from_agent: Optional[Any] = None, messages: str | list[dict[str, Any]] | None = None):
         """Handle the events for the LLM call.
 
         Args:
diff --git a/src/crewai/utilities/events/llm_events.py b/src/crewai/utilities/events/llm_events.py
index 6dbb470b8..74101a041 100644
--- a/src/crewai/utilities/events/llm_events.py
+++ b/src/crewai/utilities/events/llm_events.py
@@ -58,7 +58,7 @@ class LLMCallCompletedEvent(LLMEventBase):
     """Event emitted when a LLM call completes"""
 
     type: str = "llm_call_completed"
-    messages: Union[str, List[Dict[str, Any]]]
+    messages: str | list[dict[str, Any]] | None = None
     response: Any
     call_type: LLMCallType
 
diff --git a/tests/llm_test.py b/tests/llm_test.py
index 36fc2dfcb..1065876af 100644
--- a/tests/llm_test.py
+++ b/tests/llm_test.py
@@ -601,7 +601,7 @@ def test_handle_streaming_tool_calls(get_weather_tool_schema, mock_emit):
 def test_handle_streaming_tool_calls_with_error(get_weather_tool_schema, mock_emit):
     def get_weather_error(location):
         raise Exception("Error")
-        
+
     llm = LLM(model="openai/gpt-4o", stream=True)
     response = llm.call(
         messages=[
@@ -619,7 +619,7 @@ def test_handle_streaming_tool_calls_with_error(get_weather_tool_schema, mock_em
         expected_stream_chunk=9,
         expected_completed_llm_call=1,
         expected_tool_usage_started=1,
-        expected_tool_usage_error=1,    
+        expected_tool_usage_error=1,
         expected_final_chunk_result=expected_final_chunk_result,
     )