diff --git a/litellm/utils.py b/litellm/utils.py
index 75de4f333ac..f685d89d842 100644
--- a/litellm/utils.py
+++ b/litellm/utils.py
@@ -5219,7 +5219,9 @@ def _get_potential_model_names(model: str, custom_llm_provider: str | None) -> P
             combined_model_name = f"{cost_map_prefix}/{split_model}"
         elif cost_map_prefix != custom_llm_provider and model.startswith(cost_map_prefix + "/"):
             split_model = model.split("/", 1)[1]
-            combined_model_name = model if model.startswith(cost_map_prefix + "/") else f"{cost_map_prefix}/{split_model}"
+            combined_model_name = (
+                model if model.startswith(cost_map_prefix + "/") else f"{cost_map_prefix}/{split_model}"
+            )
         else:
             split_model = model
             combined_model_name = f"{cost_map_prefix}/{model}"
diff --git a/tests/test_litellm/test_vertex_claude_sonnet5_cost_parity.py b/tests/test_litellm/test_vertex_claude_sonnet5_cost_parity.py
index 6a3eb901745..63826b0df45 100644
--- a/tests/test_litellm/test_vertex_claude_sonnet5_cost_parity.py
+++ b/tests/test_litellm/test_vertex_claude_sonnet5_cost_parity.py
@@ -10,8 +10,6 @@ suffix ``-5`` as a Vertex publish version and rewrote bare ids to
 
 from __future__ import annotations
 
-import os
-
 import pytest
 
 import litellm