diff --git a/litellm/responses/litellm_completion_transformation/transformation.py b/litellm/responses/litellm_completion_transformation/transformation.py
index 8d790024cfe..c7f8ab24de4 100644
--- a/litellm/responses/litellm_completion_transformation/transformation.py
+++ b/litellm/responses/litellm_completion_transformation/transformation.py
@@ -337,7 +337,7 @@ class LiteLLMCompletionResponsesConfig:
                 api_base=api_base,
             )
         except Exception as e:  # noqa: BLE001  # a capability probe must never fail the request it probes for
-            verbose_logger.debug(f"responses bridge: reasoning effort mode check failed: {e}")
+            verbose_logger.debug("responses bridge: reasoning effort mode check failed: %s", e)
             return False
         return model_info.get("mode") == "responses"