diff --git a/vllm/model_executor/model_loader.py b/vllm/model_executor/model_loader.py
index e7580f2168..9dcfd968b4 100644
--- a/vllm/model_executor/model_loader.py
+++ b/vllm/model_executor/model_loader.py
@@ -27,6 +27,8 @@ _MODEL_REGISTRY = {
     "LlamaForCausalLM": LlamaForCausalLM,
     "LLaMAForCausalLM": LlamaForCausalLM,  # For decapoda-research/llama-*
     "MistralForCausalLM": MistralForCausalLM,
+    # transformers's mpt class has lower case
+    "MptForCausalLM": MPTForCausalLM,
     "MPTForCausalLM": MPTForCausalLM,
     "OPTForCausalLM": OPTForCausalLM,
     "QWenLMHeadModel": QWenLMHeadModel,