diff --git a/openhands-sdk/openhands/sdk/llm/options/chat_options.py b/openhands-sdk/openhands/sdk/llm/options/chat_options.py
index 7f29acd8db..bb3c8fef5f 100644
--- a/openhands-sdk/openhands/sdk/llm/options/chat_options.py
+++ b/openhands-sdk/openhands/sdk/llm/options/chat_options.py
@@ -39,9 +39,14 @@ def select_chat_options(
         if llm.reasoning_effort is not None:
             out["reasoning_effort"] = llm.reasoning_effort
 
-        # All reasoning models ignore temp/top_p
-        out.pop("temperature", None)
-        out.pop("top_p", None)
+        # OpenAI reasoning models (o1, o3) ignore temp/top_p
+        # Gemini models DO respect temperature, so we only pop for OpenAI
+        model_lower = llm.model.lower()
+        # Normalize to basename so provider-prefixed IDs like "openai/o1" are handled
+        model_name = model_lower.split("/")[-1]
+        if model_name.startswith(("o1", "o3")):
+            out.pop("temperature", None)
+            out.pop("top_p", None)
 
         # Gemini 2.5-pro default to low if not set
         if "gemini-2.5-pro" in llm.model: