diff --git a/specification/cognitiveservices/OpenAI.Inference/models/audio/audio_transcription.tsp b/specification/cognitiveservices/OpenAI.Inference/models/audio/audio_transcription.tsp
index bed16d4c7338..aefc8d2a03db 100644
--- a/specification/cognitiveservices/OpenAI.Inference/models/audio/audio_transcription.tsp
+++ b/specification/cognitiveservices/OpenAI.Inference/models/audio/audio_transcription.tsp
@@ -104,7 +104,7 @@ model AudioTranscriptionOptions {
   """)
   @added(ServiceApiVersions.v2024_04_01_Preview)
   @encodedName("application/json", "timestamp_granularities")
-  timestampGranularities?: AudioTranscriptionTimestampGranularity[] = [
+  timestampGranularities?: AudioTranscriptionTimestampGranularity[] = #[
     AudioTranscriptionTimestampGranularity.segment
   ];