diff --git a/aider/coders/base_coder.py b/aider/coders/base_coder.py
index 6158e7a77..2b90dbb5a 100755
--- a/aider/coders/base_coder.py
+++ b/aider/coders/base_coder.py
@@ -1073,7 +1073,7 @@ class Coder:
                 self.warming_pings_left -= 1
                 self.next_cache_warm = time.time() + delay
 
-                kwargs = self.main_model.extra_params or dict()
+                kwargs = dict(self.main_model.extra_params) or dict()
                 kwargs["max_tokens"] = 1
 
                 try: