diff --git a/chatmock/utils.py b/chatmock/utils.py
index 247f27f..89e6f3a 100644
--- a/chatmock/utils.py
+++ b/chatmock/utils.py
@@ -409,7 +409,7 @@ def sse_translate_chat(
                             "choices": [
                                 {
                                     "index": 0,
-                                    "delta": {"reasoning_summary": delta_txt},
+                                    "delta": {"reasoning_summary": delta_txt, "reasoning": delta_txt},
                                     "finish_reason": None,
                                 }
                             ],