diff --git a/litellm/llms/bedrock/chat/invoke_transformations/anthropic_claude3_transformation.py b/litellm/llms/bedrock/chat/invoke_transformations/anthropic_claude3_transformation.py
index 7a95356d054..1d615d8df7e 100644
--- a/litellm/llms/bedrock/chat/invoke_transformations/anthropic_claude3_transformation.py
+++ b/litellm/llms/bedrock/chat/invoke_transformations/anthropic_claude3_transformation.py
@@ -173,7 +173,7 @@ class AmazonAnthropicClaudeConfig(AmazonInvokeConfig, AnthropicConfig):
         if not (
             _supports_factory(
                 model=model,
-                custom_llm_provider=None,
+                custom_llm_provider="bedrock",
                 key="supports_output_config",
             )
             or AnthropicConfig._model_supports_effort_param(model)
diff --git a/litellm/llms/bedrock/messages/invoke_transformations/anthropic_claude3_transformation.py b/litellm/llms/bedrock/messages/invoke_transformations/anthropic_claude3_transformation.py
index 49f4bbfb440..8451d310578 100644
--- a/litellm/llms/bedrock/messages/invoke_transformations/anthropic_claude3_transformation.py
+++ b/litellm/llms/bedrock/messages/invoke_transformations/anthropic_claude3_transformation.py
@@ -564,7 +564,7 @@ class AmazonAnthropicClaudeMessagesConfig(
         if not (
             _supports_factory(
                 model=model,
-                custom_llm_provider=None,
+                custom_llm_provider="bedrock",
                 key="supports_output_config",
             )
             or AnthropicConfig._model_supports_effort_param(model)
diff --git a/tests/test_litellm/llms/bedrock/chat/invoke_transformations/test_bedrock_chat_invoke_transformations_anthropic_claude3_transformation.py b/tests/test_litellm/llms/bedrock/chat/invoke_transformations/test_bedrock_chat_invoke_transformations_anthropic_claude3_transformation.py
index 066a4eedf42..b2e254901f4 100644
--- a/tests/test_litellm/llms/bedrock/chat/invoke_transformations/test_bedrock_chat_invoke_transformations_anthropic_claude3_transformation.py
+++ b/tests/test_litellm/llms/bedrock/chat/invoke_transformations/test_bedrock_chat_invoke_transformations_anthropic_claude3_transformation.py
@@ -449,7 +449,7 @@ def test_bedrock_chat_invoke_checks_output_config_support_with_bedrock_provider(
 
     mock_supports_factory.assert_called_once_with(
         model="us.anthropic.claude-opus-4-7",
-        custom_llm_provider=None,
+        custom_llm_provider="bedrock",
         key="supports_output_config",
     )
     assert result["output_config"] == {"effort": "high"}
diff --git a/tests/test_litellm/llms/bedrock/messages/invoke_transformations/test_anthropic_claude3_transformation.py b/tests/test_litellm/llms/bedrock/messages/invoke_transformations/test_anthropic_claude3_transformation.py
index 4af4f8fd50e..2e315a535f0 100644
--- a/tests/test_litellm/llms/bedrock/messages/invoke_transformations/test_anthropic_claude3_transformation.py
+++ b/tests/test_litellm/llms/bedrock/messages/invoke_transformations/test_anthropic_claude3_transformation.py
@@ -694,7 +694,7 @@ def test_bedrock_messages_checks_output_config_support_with_bedrock_provider():
 
     mock_supports_factory.assert_called_with(
         model="us.anthropic.claude-opus-4-7",
-        custom_llm_provider=None,
+        custom_llm_provider="bedrock",
         key="supports_output_config",
     )
     assert result["output_config"] == {"effort": "high"}