diff --git a/examples/customize/llms/custom_llm.py b/examples/customize/llms/custom_llm.py
index e035048c..0722124b 100644
--- a/examples/customize/llms/custom_llm.py
+++ b/examples/customize/llms/custom_llm.py
@@ -1,6 +1,6 @@
 import random
 import string
-from typing import Any
+from typing import Any, Optional
 
 from neo4j_graphrag.llm import LLMInterface, LLMResponse
 
@@ -9,13 +9,23 @@ class CustomLLM(LLMInterface):
     def __init__(self, model_name: str, **kwargs: Any):
         super().__init__(model_name, **kwargs)
 
-    def invoke(self, input: str) -> LLMResponse:
+    def invoke(
+        self,
+        input: str,
+        message_history: Optional[list[dict[str, str]]] = None,
+        system_instruction: Optional[str] = None,
+    ) -> LLMResponse:
         content: str = (
             self.model_name + ": " + "".join(random.choices(string.ascii_letters, k=30))
         )
         return LLMResponse(content=content)
 
-    async def ainvoke(self, input: str) -> LLMResponse:
+    async def ainvoke(
+        self,
+        input: str,
+        message_history: Optional[list[dict[str, str]]] = None,
+        system_instruction: Optional[str] = None,
+    ) -> LLMResponse:
         raise NotImplementedError()
 
 
diff --git a/src/neo4j_graphrag/llm/mistralai_llm.py b/src/neo4j_graphrag/llm/mistralai_llm.py
index 6b42cac5..3c2d7292 100644
--- a/src/neo4j_graphrag/llm/mistralai_llm.py
+++ b/src/neo4j_graphrag/llm/mistralai_llm.py
@@ -15,7 +15,7 @@
 from __future__ import annotations
 
 import os
-from typing import Any, Optional
+from typing import Any, Optional, cast
 from pydantic import ValidationError
 
 from neo4j_graphrag.exceptions import LLMGenerationError
@@ -31,8 +31,8 @@
     from mistralai import Mistral, Messages
     from mistralai.models.sdkerror import SDKError
 except ImportError:
-    Mistral = None
-    SDKError = None
+    Mistral = None  # type: ignore
+    SDKError = None  # type: ignore
 
 
 class MistralAILLM(LLMInterface):
@@ -85,7 +85,7 @@ def get_messages(
                 raise LLMGenerationError(e.errors()) from e
             messages.extend(message_history)
         messages.append(UserMessage(content=input).model_dump())
-        return messages
+        return cast(list[Messages], messages)
 
     def invoke(
         self,
diff --git a/tests/unit/llm/test_anthropic_llm.py b/tests/unit/llm/test_anthropic_llm.py
index e17b1ec2..13e57498 100644
--- a/tests/unit/llm/test_anthropic_llm.py
+++ b/tests/unit/llm/test_anthropic_llm.py
@@ -76,7 +76,7 @@ def test_anthropic_invoke_with_message_history_happy_path(mock_anthropic: Mock)
     response = llm.invoke(question, message_history)
     assert response.content == "generated text"
     message_history.append({"role": "user", "content": question})
-    llm.client.messages.create.assert_called_once_with(
+    llm.client.messages.create.assert_called_once_with(  # type: ignore[attr-defined]
         messages=message_history,
         model="claude-3-opus-20240229",
         system=system_instruction,
diff --git a/tests/unit/llm/test_mistralai_llm.py b/tests/unit/llm/test_mistralai_llm.py
index aab8eeb1..4e7ee6fd 100644
--- a/tests/unit/llm/test_mistralai_llm.py
+++ b/tests/unit/llm/test_mistralai_llm.py
@@ -71,7 +71,7 @@ def test_mistralai_llm_invoke_with_message_history(mock_mistral: Mock) -> None:
     messages = [{"role": "system", "content": system_instruction}]
     messages.extend(message_history)
     messages.append({"role": "user", "content": question})
-    llm.client.chat.complete.assert_called_once_with(
+    llm.client.chat.complete.assert_called_once_with(  # type: ignore[attr-defined]
         messages=messages,
         model=model,
     )
diff --git a/tests/unit/llm/test_ollama_llm.py b/tests/unit/llm/test_ollama_llm.py
index 779bf902..76272520 100644
--- a/tests/unit/llm/test_ollama_llm.py
+++ b/tests/unit/llm/test_ollama_llm.py
@@ -58,7 +58,7 @@ def test_ollama_llm_happy_path(mock_import: Mock) -> None:
         {"role": "system", "content": system_instruction},
         {"role": "user", "content": question},
     ]
-    llm.client.chat.assert_called_once_with(
+    llm.client.chat.assert_called_once_with(  # type: ignore[attr-defined]
         model=model, messages=messages, options=model_params
     )
 
@@ -89,7 +89,7 @@ def test_ollama_invoke_with_message_history_happy_path(mock_import: Mock) -> Non
     messages = [{"role": "system", "content": system_instruction}]
     messages.extend(message_history)
     messages.append({"role": "user", "content": question})
-    llm.client.chat.assert_called_once_with(
+    llm.client.chat.assert_called_once_with(  # type: ignore[attr-defined]
         model=model, messages=messages, options=model_params
     )