diff --git a/aider/coders/base_coder.py b/aider/coders/base_coder.py
index 0bee6d5cd..002aa8517 100755
--- a/aider/coders/base_coder.py
+++ b/aider/coders/base_coder.py
@@ -693,7 +693,7 @@ class Coder:
             raise Exception("No data found in openai response!")
 
         tokens = None
-        if hasattr(completion, "usage"):
+        if hasattr(completion, "usage") and completion.usage is not None:
             prompt_tokens = completion.usage.prompt_tokens
             completion_tokens = completion.usage.completion_tokens