diff --git a/deployments/ai-stack/openwebui-models/image_studio.json b/deployments/ai-stack/openwebui-models/image_studio.json
index c3b7087..fc7c2a0 100644
--- a/deployments/ai-stack/openwebui-models/image_studio.json
+++ b/deployments/ai-stack/openwebui-models/image_studio.json
@@ -8,7 +8,9 @@
       "temperature": 0.5,
       "top_p": 0.9,
       "function_calling": "native",
-      "tool_choice": "required"
+      "custom_params": {
+        "tool_choice": "required"
+      }
     },
     "meta": {
       "profile_image_url": "/static/favicon.png",