diff --git a/ads/llm/langchain/plugins/chat_models/oci_data_science.py b/ads/llm/langchain/plugins/chat_models/oci_data_science.py
index 9785dd0fd..b2b0e5f16 100644
--- a/ads/llm/langchain/plugins/chat_models/oci_data_science.py
+++ b/ads/llm/langchain/plugins/chat_models/oci_data_science.py
@@ -93,7 +93,7 @@ class ChatOCIModelDeployment(BaseChatModel, BaseOCIModelDeployment):
     Key init args — client params:
         auth: dict
             ADS auth dictionary for OCI authentication.
-        headers: Optional[Dict]
+        default_headers: Optional[Dict]
             The headers to be added to the Model Deployment request.
 
     Instantiate:
@@ -111,7 +111,7 @@ class ChatOCIModelDeployment(BaseChatModel, BaseOCIModelDeployment):
                     "temperature": 0.2,
                     # other model parameters ...
                 },
-                headers={
+                default_headers={
                     "route": "/v1/chat/completions",
                     # other request headers ...
                 },
@@ -263,9 +263,6 @@ def _construct_json_body(self, messages: list, params: dict) -> dict:
     """Stop words to use when generating. Model output is cut off
     at the first occurrence of any of these substrings."""
 
-    headers: Optional[Dict[str, Any]] = {"route": DEFAULT_INFERENCE_ENDPOINT_CHAT}
-    """The headers to be added to the Model Deployment request."""
-
     @model_validator(mode="before")
     @classmethod
     def validate_openai(cls, values: Any) -> Any:
@@ -300,6 +297,25 @@ def _default_params(self) -> Dict[str, Any]:
             "stream": self.streaming,
         }
 
+    def _headers(
+        self, is_async: Optional[bool] = False, body: Optional[dict] = None
+    ) -> Dict:
+        """Construct and return the headers for a request.
+
+        Args:
+            is_async (bool, optional): Indicates if the request is asynchronous.
+                Defaults to `False`.
+            body (optional): The request body to be included in the headers if
+                the request is asynchronous.
+
+        Returns:
+            Dict: A dictionary containing the appropriate headers for the request.
+        """
+        return {
+            "route": DEFAULT_INFERENCE_ENDPOINT_CHAT,
+            **super()._headers(is_async=is_async, body=body),
+        }
+
     def _generate(
         self,
         messages: List[BaseMessage],
diff --git a/ads/llm/langchain/plugins/llms/oci_data_science_model_deployment_endpoint.py b/ads/llm/langchain/plugins/llms/oci_data_science_model_deployment_endpoint.py
index 3be494270..20f1fae07 100644
--- a/ads/llm/langchain/plugins/llms/oci_data_science_model_deployment_endpoint.py
+++ b/ads/llm/langchain/plugins/llms/oci_data_science_model_deployment_endpoint.py
@@ -85,7 +85,7 @@ class BaseOCIModelDeployment(Serializable):
     max_retries: int = 3
     """Maximum number of retries to make when generating."""
 
-    headers: Optional[Dict[str, Any]] = {"route": DEFAULT_INFERENCE_ENDPOINT}
+    default_headers: Optional[Dict[str, Any]] = None
     """The headers to be added to the Model Deployment request."""
 
     @model_validator(mode="before")
@@ -127,7 +127,7 @@ def _headers(
         Returns:
             Dict: A dictionary containing the appropriate headers for the request.
         """
-        headers = self.headers
+        headers = self.default_headers or {}
         if is_async:
             signer = self.auth["signer"]
             _req = requests.Request("POST", self.endpoint, json=body)
@@ -485,6 +485,25 @@ def _identifying_params(self) -> Dict[str, Any]:
             **self._default_params,
         }
 
+    def _headers(
+        self, is_async: Optional[bool] = False, body: Optional[dict] = None
+    ) -> Dict:
+        """Construct and return the headers for a request.
+
+        Args:
+            is_async (bool, optional): Indicates if the request is asynchronous.
+                Defaults to `False`.
+            body (optional): The request body to be included in the headers if
+                the request is asynchronous.
+
+        Returns:
+            Dict: A dictionary containing the appropriate headers for the request.
+        """
+        return {
+            "route": DEFAULT_INFERENCE_ENDPOINT,
+            **super()._headers(is_async=is_async, body=body),
+        }
+
     def _generate(
         self,
         prompts: List[str],
diff --git a/tests/unitary/with_extras/langchain/chat_models/test_oci_data_science.py b/tests/unitary/with_extras/langchain/chat_models/test_oci_data_science.py
index e7d32d2de..197171353 100644
--- a/tests/unitary/with_extras/langchain/chat_models/test_oci_data_science.py
+++ b/tests/unitary/with_extras/langchain/chat_models/test_oci_data_science.py
@@ -26,7 +26,7 @@
 CONST_ENDPOINT = "https://oci.endpoint/ocid/predict"
 CONST_PROMPT = "This is a prompt."
 CONST_COMPLETION = "This is a completion."
-CONST_ENDPOINT = "/v1/chat/completions"
+CONST_COMPLETION_ROUTE = "/v1/chat/completions"
 CONST_COMPLETION_RESPONSE = {
     "id": "chat-123456789",
     "object": "chat.completion",
@@ -124,7 +124,7 @@ def mocked_requests_post(url: str, **kwargs: Any) -> MockResponse:
 def test_invoke_vllm(*args: Any) -> None:
     """Tests invoking vLLM endpoint."""
     llm = ChatOCIModelDeploymentVLLM(endpoint=CONST_ENDPOINT, model=CONST_MODEL_NAME)
-    assert llm.headers == {"route": CONST_ENDPOINT}
+    assert llm._headers().get("route") == CONST_COMPLETION_ROUTE
     output = llm.invoke(CONST_PROMPT)
     assert isinstance(output, AIMessage)
     assert output.content == CONST_COMPLETION
@@ -137,7 +137,7 @@ def test_invoke_vllm(*args: Any) -> None:
 def test_invoke_tgi(*args: Any) -> None:
     """Tests invoking TGI endpoint using OpenAI Spec."""
     llm = ChatOCIModelDeploymentTGI(endpoint=CONST_ENDPOINT, model=CONST_MODEL_NAME)
-    assert llm.headers == {"route": CONST_ENDPOINT}
+    assert llm._headers().get("route") == CONST_COMPLETION_ROUTE
     output = llm.invoke(CONST_PROMPT)
     assert isinstance(output, AIMessage)
     assert output.content == CONST_COMPLETION
@@ -152,7 +152,7 @@ def test_stream_vllm(*args: Any) -> None:
     llm = ChatOCIModelDeploymentVLLM(
         endpoint=CONST_ENDPOINT, model=CONST_MODEL_NAME, streaming=True
     )
-    assert llm.headers == {"route": CONST_ENDPOINT}
+    assert llm._headers().get("route") == CONST_COMPLETION_ROUTE
     output = None
     count = 0
     for chunk in llm.stream(CONST_PROMPT):
@@ -191,7 +191,7 @@ async def test_stream_async(*args: Any) -> None:
     llm = ChatOCIModelDeploymentVLLM(
         endpoint=CONST_ENDPOINT, model=CONST_MODEL_NAME, streaming=True
     )
-    assert llm.headers == {"route": CONST_ENDPOINT}
+    assert llm._headers().get("route") == CONST_COMPLETION_ROUTE
     with mock.patch.object(
         llm,
         "_aiter_sse",
diff --git a/tests/unitary/with_extras/langchain/llms/test_oci_model_deployment_endpoint.py b/tests/unitary/with_extras/langchain/llms/test_oci_model_deployment_endpoint.py
index 14cdda3ec..825c49d87 100644
--- a/tests/unitary/with_extras/langchain/llms/test_oci_model_deployment_endpoint.py
+++ b/tests/unitary/with_extras/langchain/llms/test_oci_model_deployment_endpoint.py
@@ -24,7 +24,7 @@
 CONST_ENDPOINT = "https://oci.endpoint/ocid/predict"
 CONST_PROMPT = "This is a prompt."
 CONST_COMPLETION = "This is a completion."
-CONST_ENDPOINT = "/v1/completions"
+CONST_COMPLETION_ROUTE = "/v1/completions"
 CONST_COMPLETION_RESPONSE = {
     "choices": [
         {
@@ -117,7 +117,7 @@ async def mocked_async_streaming_response(
 def test_invoke_vllm(*args: Any) -> None:
     """Tests invoking vLLM endpoint."""
     llm = OCIModelDeploymentVLLM(endpoint=CONST_ENDPOINT, model=CONST_MODEL_NAME)
-    assert llm.headers == {"route": CONST_ENDPOINT}
+    assert llm._headers().get("route") == CONST_COMPLETION_ROUTE
     output = llm.invoke(CONST_PROMPT)
     assert output == CONST_COMPLETION
 
@@ -130,7 +130,7 @@ def test_stream_tgi(*args: Any) -> None:
     llm = OCIModelDeploymentTGI(
         endpoint=CONST_ENDPOINT, model=CONST_MODEL_NAME, streaming=True
     )
-    assert llm.headers == {"route": CONST_ENDPOINT}
+    assert llm._headers().get("route") == CONST_COMPLETION_ROUTE
     output = ""
     count = 0
     for chunk in llm.stream(CONST_PROMPT):
@@ -148,7 +148,7 @@ def test_generate_tgi(*args: Any) -> None:
     llm = OCIModelDeploymentTGI(
         endpoint=CONST_ENDPOINT, api="/generate", model=CONST_MODEL_NAME
     )
-    assert llm.headers == {"route": CONST_ENDPOINT}
+    assert llm._headers().get("route") == CONST_COMPLETION_ROUTE
     output = llm.invoke(CONST_PROMPT)
     assert output == CONST_COMPLETION
 
@@ -167,7 +167,7 @@ async def test_stream_async(*args: Any) -> None:
     llm = OCIModelDeploymentTGI(
         endpoint=CONST_ENDPOINT, model=CONST_MODEL_NAME, streaming=True
     )
-    assert llm.headers == {"route": CONST_ENDPOINT}
+    assert llm._headers().get("route") == CONST_COMPLETION_ROUTE
     with mock.patch.object(
         llm,
         "_aiter_sse",