diff --git a/litellm/llms/azure_ai/anthropic/transformation.py b/litellm/llms/azure_ai/anthropic/transformation.py
index 0b588b6cc52..a25559ecef3 100644
--- a/litellm/llms/azure_ai/anthropic/transformation.py
+++ b/litellm/llms/azure_ai/anthropic/transformation.py
@@ -115,22 +115,24 @@ class AzureAnthropicConfig(AnthropicConfig):
         self,
         model: str,
         messages: list[AllMessageValues],
-        optional_params: dict,
-        litellm_params: dict,
-        headers: dict,
-    ) -> dict:
+        optional_params: dict[str, object],
+        litellm_params: dict[str, object],
+        headers: dict[str, object],
+    ) -> dict[str, object]:
         """
         Transform request using parent AnthropicConfig, then remove unsupported params.
         Azure Anthropic doesn't support extra_body, max_retries, or stream_options parameters.
         """
         _promote_extra_body_to_optional_params(optional_params)
 
-        data: Final = super().transform_request(
-            model=model,
-            messages=messages,
-            optional_params=optional_params,
-            litellm_params=litellm_params,
-            headers=headers,
-        )
+        data: Final[dict[str, object]] = {
+            **super().transform_request(
+                model=model,
+                messages=messages,
+                optional_params=optional_params,
+                litellm_params=litellm_params,
+                headers=headers,
+            )
+        }
 
         return {key: value for key, value in data.items() if key not in _AZURE_ANTHROPIC_NON_BODY_PARAMS}
diff --git a/tests/unit/test_azure_ad_token_credential_resolution.py b/tests/unit/test_azure_ad_token_credential_resolution.py
index 07106582d0e..c0469842c0f 100644
--- a/tests/unit/test_azure_ad_token_credential_resolution.py
+++ b/tests/unit/test_azure_ad_token_credential_resolution.py
@@ -214,7 +214,7 @@ class TestRouterCredentialResolutionS3OutputBucket:
 def test_azure_anthropic_request_body_does_not_include_azure_credentials() -> None:
     from litellm.llms.azure_ai.anthropic.transformation import AzureAnthropicConfig
 
-    credential_params: Final = {
+    credential_params: Final[dict[str, str]] = {
         "api_key": "test-api-key",
         "azure_ad_token": "test-access-token",
         "azure_ad_token_provider": "test-token-provider",
@@ -225,13 +225,13 @@ def test_azure_anthropic_request_body_does_not_include_azure_credentials() -> No
         "azure_username": "test-username",
         "azure_password": "test-password",
     }
-    output_config: Final = {"format": {"type": "json_object"}}
-    extra_body_params: Final = {
+    output_config: Final[dict[str, dict[str, str]]] = {"format": {"type": "json_object"}}
+    extra_body_params: Final[dict[str, str]] = {
         key: value
         for key, value in credential_params.items()
         if key not in {"api_key", "azure_ad_token"}
     }
-    body: Final = AzureAnthropicConfig().transform_request(
+    body: Final[dict[str, object]] = AzureAnthropicConfig().transform_request(
         model="claude-3-5-sonnet-20241022",
         messages=[{"role": "user", "content": "hello"}],
         optional_params={