diff --git a/src/utils/common.py b/src/utils/common.py
index 396c91d7..b784d1fc 100644
--- a/src/utils/common.py
+++ b/src/utils/common.py
@@ -55,11 +55,12 @@ require_version("trl>=0.4.1", "To fix: pip install trl>=0.4.1")
 logger = get_logger(__name__)
 
 
-def init_adapter(
+def _init_adapter(
         model: PreTrainedModel,
         model_args: ModelArguments,
         finetuning_args: FinetuningArguments,
-        is_trainable: bool
+        is_trainable: bool,
+        is_mergeable: bool
 ) -> PreTrainedModel:
     r"""
     Initializes the adapters.
@@ -84,16 +85,19 @@ def init_adapter(
             else:
                 param.data = param.data.to(torch.float32)
 
-    if finetuning_args.finetuning_type != "lora" and model_args.checkpoint_dir is not None:
-        assert len(model_args.checkpoint_dir) == 1, "Only LoRA tuning accepts multiple checkpoints."
-        load_trainable_params(model, model_args.checkpoint_dir[0]) # load model checkpoints for non-peft methods
+    if model_args.checkpoint_dir is not None:
+        if finetuning_args.finetuning_type != "lora":
+            assert is_mergeable and len(model_args.checkpoint_dir) == 1, "Only LoRA tuning accepts multiple checkpoints."
+            load_trainable_params(model, model_args.checkpoint_dir[0]) # load model checkpoints for non-peft methods
+        else:
+            assert is_mergeable or len(model_args.checkpoint_dir) == 1, "Quantized model only accepts a single checkpoint."
 
     if finetuning_args.finetuning_type == "lora":
         logger.info("Fine-tuning method: LoRA")
         lastest_checkpoint = None
 
         if model_args.checkpoint_dir is not None:
-            if is_trainable and model_args.resume_lora_training: # continually train on the lora weights
+            if (is_trainable and model_args.resume_lora_training) or (not is_mergeable): # continually train on the lora weights
                 checkpoints_to_merge, lastest_checkpoint = model_args.checkpoint_dir[:-1], model_args.checkpoint_dir[-1]
             else:
                 checkpoints_to_merge = model_args.checkpoint_dir
@@ -105,8 +109,8 @@ def init_adapter(
             if len(checkpoints_to_merge) > 0:
                 logger.info("Merged {} model checkpoint(s).".format(len(checkpoints_to_merge)))
 
-            if lastest_checkpoint is not None: # resume lora training
-                model = PeftModel.from_pretrained(model, lastest_checkpoint, is_trainable=True)
+            if lastest_checkpoint is not None: # resume lora training or quantized inference
+                model = PeftModel.from_pretrained(model, lastest_checkpoint, is_trainable=is_trainable)
 
         if is_trainable and lastest_checkpoint is None: # create new lora weights while training
             lora_config = LoraConfig(
@@ -159,11 +163,15 @@ def load_pretrained(
     tokenizer.pad_token_id = 0 if tokenizer.pad_token_id is None else tokenizer.pad_token_id # set as the <unk> token
 
     config = AutoConfig.from_pretrained(model_args.model_name_or_path, **config_kwargs)
+    is_mergeable = True
 
     # Quantization configurations (using bitsandbytes library).
     if model_args.quantization_bit is not None:
         assert model_args.quantization_bit == 8, "We only accept 8-bit quantization."
-        require_version("bitsandbytes>=0.39.0", "To fix: pip install bitsandbytes>=0.39.1")
+        require_version("bitsandbytes>=0.39.0", "To fix: pip install bitsandbytes>=0.39.0")
+        #require_version("transformers>=4.30.0.dev0", "To fix: pip install git+https://github.com/huggingface/transformers.git")
+        #require_version("peft>=0.4.0.dev0", "To fix: pip install git+https://github.com/huggingface/peft.git")
+        #require_version("accelerate>=0.20.0.dev0", "To fix: pip install git+https://github.com/huggingface/accelerate.git")
         from bitsandbytes.cuda_setup.main import get_compute_capability, get_cuda_lib_handle, is_cublasLt_compatible
         cuda = get_cuda_lib_handle()
         cc = get_compute_capability(cuda)
@@ -171,6 +179,7 @@ def load_pretrained(
 
         config_kwargs["load_in_8bit"] = True
         config_kwargs["device_map"] = "auto" # it should not be specified outside of load_in_8bit
+        is_mergeable = False
         logger.info("Quantizing model to {} bit.".format(model_args.quantization_bit))
 
     # Load and prepare pretrained models (without valuehead).
@@ -182,7 +191,7 @@ def load_pretrained(
         **config_kwargs
     )
     model = prepare_model_for_training(model) if is_trainable else model
-    model = init_adapter(model, model_args, finetuning_args, is_trainable)
+    model = _init_adapter(model, model_args, finetuning_args, is_trainable, is_mergeable)
 
     if stage == "rm" or stage == "ppo": # add value head
         model = AutoModelForCausalLMWithValueHead.from_pretrained(model)