diff --git a/aider/coders/base_coder.py b/aider/coders/base_coder.py
index 1cb6b6395..823b418a0 100755
--- a/aider/coders/base_coder.py
+++ b/aider/coders/base_coder.py
@@ -967,7 +967,8 @@ class Coder:
         chunks = ChatChunks()
 
         chunks.system = [
-            dict(role="system", content=main_sys),
+            dict(role="user", content=main_sys),
+            dict(role="assistant", content="Ok."),
         ]
         chunks.examples = example_messages
 
diff --git a/aider/sendchat.py b/aider/sendchat.py
index 7301a602a..af3d126e0 100644
--- a/aider/sendchat.py
+++ b/aider/sendchat.py
@@ -60,7 +60,7 @@ def send_completion(
     kwargs = dict(
         model=model_name,
         messages=messages,
-        temperature=temperature,
+        # temperature=temperature,
         stream=stream,
     )
 
diff --git a/benchmark/benchmark.py b/benchmark/benchmark.py
index 3d559b9be..2b459a1f7 100755
--- a/benchmark/benchmark.py
+++ b/benchmark/benchmark.py
@@ -549,7 +549,8 @@ def run_test_real(
         chat_history_file=history_fname,
     )
 
-    main_model = models.Model(model_name)
+    weak_model = "gpt-4o-mini"
+    main_model = models.Model(model_name, weak_model)
     edit_format = edit_format or main_model.edit_format
 
     dump(main_model)