diff --git a/litellm/llms/anthropic/chat/transformation.py b/litellm/llms/anthropic/chat/transformation.py
index 5b12c4a6de3..136ed2e58fd 100644
--- a/litellm/llms/anthropic/chat/transformation.py
+++ b/litellm/llms/anthropic/chat/transformation.py
@@ -647,14 +647,9 @@ class AnthropicConfig(AnthropicModelInfo, BaseConfig):
                 new_v.append(v)
             if len(new_v) > 0:
                 new_stop = new_v
-        return new_stop
-
-    @staticmethod
-    def _map_reasoning_effort(
-        reasoning_effort: Optional[Union[REASONING_EFFORT, str]], 
-        model: str,
-    ) -> Optional[AnthropicThinkingParam]:
         if AnthropicConfig._is_claude_opus_4_6(model):
+            if reasoning_effort is None:
+                return None
             return AnthropicThinkingParam(
                 type="adaptive",
             )