diff --git a/browser_use/llm/anthropic/chat.py b/browser_use/llm/anthropic/chat.py
index 861fd5b0b..e5667d7f4 100644
--- a/browser_use/llm/anthropic/chat.py
+++ b/browser_use/llm/anthropic/chat.py
@@ -5,12 +5,12 @@ from typing import Any, TypeVar, overload
 
 import httpx
 from anthropic import (
-	NOT_GIVEN,
 	APIConnectionError,
 	APIStatusError,
 	AsyncAnthropic,
 	NotGiven,
 	RateLimitError,
+	omit,
 )
 from anthropic.types import CacheControlEphemeralParam, Message, ToolParam
 from anthropic.types.model_param import ModelParam
@@ -141,7 +141,7 @@ class ChatAnthropic(BaseChatModel):
 				response = await self.get_client().messages.create(
 					model=self.model,
 					messages=anthropic_messages,
-					system=system_prompt or NOT_GIVEN,
+					system=system_prompt or omit,
 					**self._get_client_params_for_invoke(),
 				)
 
@@ -192,7 +192,7 @@ class ChatAnthropic(BaseChatModel):
 					model=self.model,
 					messages=anthropic_messages,
 					tools=[tool],
-					system=system_prompt or NOT_GIVEN,
+					system=system_prompt or omit,
 					tool_choice=tool_choice,
 					**self._get_client_params_for_invoke(),
 				)
diff --git a/browser_use/llm/aws/chat_anthropic.py b/browser_use/llm/aws/chat_anthropic.py
index 65eba410c..233ebf047 100644
--- a/browser_use/llm/aws/chat_anthropic.py
+++ b/browser_use/llm/aws/chat_anthropic.py
@@ -4,11 +4,11 @@ from dataclasses import dataclass
 from typing import TYPE_CHECKING, Any, TypeVar, overload
 
 from anthropic import (
-	NOT_GIVEN,
 	APIConnectionError,
 	APIStatusError,
 	AsyncAnthropicBedrock,
 	RateLimitError,
+	omit,
 )
 from anthropic.types import CacheControlEphemeralParam, Message, ToolParam
 from anthropic.types.text_block import TextBlock
@@ -163,7 +163,7 @@ class ChatAnthropicBedrock(ChatAWSBedrock):
 				response = await self.get_client().messages.create(
 					model=self.model,
 					messages=anthropic_messages,
-					system=system_prompt or NOT_GIVEN,
+					system=system_prompt or omit,
 					**self._get_client_params_for_invoke(),
 				)
 
@@ -206,7 +206,7 @@ class ChatAnthropicBedrock(ChatAWSBedrock):
 					model=self.model,
 					messages=anthropic_messages,
 					tools=[tool],
-					system=system_prompt or NOT_GIVEN,
+					system=system_prompt or omit,
 					tool_choice=tool_choice,
 					**self._get_client_params_for_invoke(),
 				)