diff --git a/src/agents/voice/events.py b/src/agents/voice/events.py
index bdcd08153..62ce6978e 100644
--- a/src/agents/voice/events.py
+++ b/src/agents/voice/events.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
-from typing import Literal, Union
+from typing import Literal
 
 from typing_extensions import TypeAlias
 
@@ -41,7 +41,6 @@ class VoiceStreamEventError:
     """The type of event."""
 
 
-VoiceStreamEvent: TypeAlias = Union[
-    VoiceStreamEventAudio, VoiceStreamEventLifecycle, VoiceStreamEventError
-]
+VoiceStreamEvent: TypeAlias = ( VoiceStreamEventAudio | VoiceStreamEventLifecycle | VoiceStreamEventError )
+
 """An event from the `VoicePipeline`, streamed via `StreamedAudioResult.stream()`."""