diff --git a/vllm/model_executor/model_loader/tensorizer.py b/vllm/model_executor/model_loader/tensorizer.py
index 757c467c4..5160d4842 100644
--- a/vllm/model_executor/model_loader/tensorizer.py
+++ b/vllm/model_executor/model_loader/tensorizer.py
@@ -764,7 +764,10 @@ def tensorize_lora_adapter(lora_path: str, tensorizer_config: TensorizerConfig):
     elif tensor_path.endswith(".bin"):
         tensors = torch.load(tensor_path, weights_only=True)
     else:
-        raise ValueError("Unsupported file: %s", tensor_path)
+        raise ValueError(
+            f"Unsupported adapter model file: {tensor_path}. "
+            f"Must be a .safetensors or .bin file."
+        )
 
     with open(config_path) as f:
         config = json.load(f)