diff --git a/.dotnet/src/Custom/RealtimeConversation/Internal/InternalRealtimeServerVadTurnDetection.Serialization.cs b/.dotnet/src/Custom/RealtimeConversation/Internal/InternalRealtimeServerVadTurnDetection.Serialization.cs
index 98aeaa1b1..83167137f 100644
--- a/.dotnet/src/Custom/RealtimeConversation/Internal/InternalRealtimeServerVadTurnDetection.Serialization.cs
+++ b/.dotnet/src/Custom/RealtimeConversation/Internal/InternalRealtimeServerVadTurnDetection.Serialization.cs
@@ -12,6 +12,12 @@ namespace OpenAI.RealtimeConversation;
 [CodeGenSerialization(nameof(SilenceDurationMs), DeserializationValueHook = nameof(DeserializeMillisecondDuration), SerializationValueHook = nameof(SerializeSilenceDurationMs))]
 internal partial class InternalRealtimeServerVadTurnDetection
 {
+    // CUSTOM: Represent millisecond durations as timespans
+    [CodeGenMember("PrefixPaddingMs")]
+    public TimeSpan? PrefixPaddingMs { get; set; }
+    [CodeGenMember("SilenceDurationms")]
+    public TimeSpan? SilenceDurationMs { get; set; }
+
     private static void DeserializeMillisecondDuration(JsonProperty property, ref TimeSpan? duration)
     {
         if (property.Value.ValueKind == JsonValueKind.Number)
diff --git a/.dotnet/src/Generated/Models/InternalRealtimeServerVadTurnDetection.cs b/.dotnet/src/Generated/Models/InternalRealtimeServerVadTurnDetection.cs
index e0ec40082..5136bd6d8 100644
--- a/.dotnet/src/Generated/Models/InternalRealtimeServerVadTurnDetection.cs
+++ b/.dotnet/src/Generated/Models/InternalRealtimeServerVadTurnDetection.cs
@@ -22,7 +22,5 @@ internal InternalRealtimeServerVadTurnDetection(ConversationTurnDetectionKind ki
         }
 
         public float? Threshold { get; set; }
-        public TimeSpan? PrefixPaddingMs { get; set; }
-        public TimeSpan? SilenceDurationMs { get; set; }
     }
 }
diff --git a/.openapi3/openapi3-openai.yaml b/.openapi3/openapi3-openai.yaml
index 2a86f0794..af215b28f 100644
--- a/.openapi3/openapi3-openai.yaml
+++ b/.openapi3/openapi3-openai.yaml
@@ -10596,11 +10596,13 @@ components:
           format: float
           default: 0.5
         prefix_padding_ms:
-          type: string
-          format: duration
+          type: integer
+          format: int32
+          default: 300
         silence_duration_ms:
-          type: string
-          format: duration
+          type: integer
+          format: int32
+          default: 200
       allOf:
         - $ref: '#/components/schemas/RealtimeTurnDetection'
     RealtimeTool:
diff --git a/.typespec/realtime/custom.tsp b/.typespec/realtime/custom.tsp
index cb2588bea..2b69f2a26 100644
--- a/.typespec/realtime/custom.tsp
+++ b/.typespec/realtime/custom.tsp
@@ -106,12 +106,8 @@ model RealtimeTurnDetection {
 model RealtimeServerVadTurnDetection extends RealtimeTurnDetection {
   type: RealtimeTurnDetectionType.server_vad;
   threshold?: float32 = 0.5;
-
-  // @encode("milliseconds", int32)
-  prefix_padding_ms?: duration; // = 300ms
-
-  // @encode("milliseconds", int32)
-  silence_duration_ms?: duration; // = 200,s
+  prefix_padding_ms?: int32 = 300;
+  silence_duration_ms?: int32 = 200;
 }
 
 union RealtimeResponseStatus {