diff --git a/tools/mypy.sh b/tools/mypy.sh
index 4e358faafe8de..e6187a08ffd98 100755
--- a/tools/mypy.sh
+++ b/tools/mypy.sh
@@ -19,7 +19,7 @@ run_mypy vllm/attention
 #run_mypy vllm/core
 run_mypy vllm/distributed
 run_mypy vllm/engine
-#run_mypy vllm/entrypoints
+run_mypy vllm/entrypoints
 run_mypy vllm/executor
 #run_mypy vllm/inputs
 run_mypy vllm/logging
diff --git a/vllm/entrypoints/llm.py b/vllm/entrypoints/llm.py
index 7ad352cd87526..2010381076c7d 100644
--- a/vllm/entrypoints/llm.py
+++ b/vllm/entrypoints/llm.py
@@ -514,10 +514,13 @@ def chat(
         # Handle multi and single conversations
         if is_list_of(messages, list):
             # messages is List[List[...]]
-            list_of_messages = messages
+            list_of_messages = cast(List[List[ChatCompletionMessageParam]],
+                                    messages)
         else:
             # messages is List[...]
-            list_of_messages = [messages]
+            list_of_messages = [
+                cast(List[ChatCompletionMessageParam], messages)
+            ]
 
         prompts: List[Union[TokensPrompt, TextPrompt]] = []