diff --git a/litellm/llms/anthropic/chat/transformation.py b/litellm/llms/anthropic/chat/transformation.py
index 8263ea4cf01..3cd19fad1fb 100644
--- a/litellm/llms/anthropic/chat/transformation.py
+++ b/litellm/llms/anthropic/chat/transformation.py
@@ -1573,6 +1573,12 @@ class AnthropicConfig(AnthropicModelInfo, BaseConfig):
                 )
         return _message
 
+    @staticmethod
+    def _strip_leaked_think_prefix(text_content: str) -> str:
+        if "</think>" not in text_content:
+            return text_content
+        return text_content.split("</think>", 1)[1].lstrip()
+
     def extract_response_content(self, completion_response: dict) -> Tuple[
         str,
         Optional[List[Any]],
@@ -1667,8 +1673,7 @@ class AnthropicConfig(AnthropicModelInfo, BaseConfig):
                 if thinking_content is not None:
                     reasoning_content += thinking_content
 
-        if "</think>" in text_content:
-            text_content = text_content.split("</think>", 1)[1].lstrip()
+        text_content = self._strip_leaked_think_prefix(text_content)
 
         return (
             text_content,
diff --git a/litellm/llms/anthropic/experimental_pass_through/adapters/transformation.py b/litellm/llms/anthropic/experimental_pass_through/adapters/transformation.py
index cfe52007c58..8e0f15e54ea 100644
--- a/litellm/llms/anthropic/experimental_pass_through/adapters/transformation.py
+++ b/litellm/llms/anthropic/experimental_pass_through/adapters/transformation.py
@@ -1385,12 +1385,12 @@ class LiteLLMAnthropicMessagesAdapter:
                 raw_id = choice.delta.tool_calls[0].id or str(uuid.uuid4())
                 tool_name = choice.delta.tool_calls[0].function.name or ""
                 base_id = raw_id
-                thought_sig: Optional[str] = None
+                thought_sig: str | None = None
                 if THOUGHT_SIGNATURE_SEPARATOR in raw_id:
                     parts = raw_id.split(THOUGHT_SIGNATURE_SEPARATOR, 1)
                     base_id = parts[0]
                     thought_sig = parts[1] if len(parts) > 1 else None
-                tool_block: Dict[str, Any] = {
+                tool_block: dict[str, Any] = {
                     "type": "tool_use",
                     "id": base_id,
                     "name": tool_name,