diff --git a/lib/tasks/llm/llms/openai_s2s.js b/lib/tasks/llm/llms/openai_s2s.js
index 6b6ae03e..2108a71b 100644
--- a/lib/tasks/llm/llms/openai_s2s.js
+++ b/lib/tasks/llm/llms/openai_s2s.js
@@ -59,7 +59,7 @@ class TaskLlmOpenAI_S2S extends Task {
     this.parent = parentTask;
 
     this.vendor = this.parent.vendor;
-    this.model = this.parent.model;
+    this.model = this.parent.model || 'gpt-4o-realtime-preview-2024-12-17';
     this.auth = this.parent.auth;
     this.connectionOptions = this.parent.connectOptions;
 
@@ -120,9 +120,9 @@ class TaskLlmOpenAI_S2S extends Task {
 
     switch (this.vendor) {
       case 'openai':
-        return 'v1/realtime?model=gpt-4o-realtime-preview-2024-10-01';
+        return 'v1/realtime?model=${this.model}';
       case 'microsoft':
-        return 'openai/realtime?api-version=2024-10-01-preview&deployment=gpt-4o-realtime-preview-1001&';
+        return `openai/realtime?api-version=2024-10-01-preview&deployment=${this.model}`;
     }
   }