diff --git a/aider/models.py b/aider/models.py
index 1397285dd..27a2dc053 100644
--- a/aider/models.py
+++ b/aider/models.py
@@ -17,7 +17,11 @@ from PIL import Image
 
 from aider.dump import dump  # noqa: F401
 from aider.llm import litellm
-from aider.sendchat import sanity_check_messages, ensure_alternating_roles, RETRY_TIMEOUT
+from aider.sendchat import (
+    RETRY_TIMEOUT,
+    ensure_alternating_roles,
+    sanity_check_messages,
+)
 
 DEFAULT_MODEL_NAME = "gpt-4o"
 ANTHROPIC_BETA_HEADER = "prompt-caching-2024-07-31,pdfs-2024-09-25"