diff --git a/model/bert_metric.py b/model/bert_metric.py
index 8d12c01..f082f1a 100644
--- a/model/bert_metric.py
+++ b/model/bert_metric.py
@@ -34,8 +34,13 @@ def __init__(self, args):
             nn.Linear(mlp_hidden_size_2, 1),
             nn.Sigmoid())
 
-        self.device = torch.device("cuda:{}".format(args.gpu))
-        self.to(self.device)
+        if args.gpu:
+            self.device = torch.device("cuda:{}".format(args.gpu))
+            self.to(self.device)
+            map_location = 'cuda:{}'.format(args.gpu)
+        else:
+            self.device = None
+            map_location = None
 
         if hasattr(args, 'checkpoint_file_name'):
             # loads checkpoint
@@ -43,7 +48,7 @@ def __init__(self, args):
                 args.checkpoint_dir_path, args.checkpoint_file_name)
             state_dict = torch.load(
                 checkpoint_file_path,
-                map_location='cuda:{}'.format(args.gpu))
+                map_location=map_location)
             self.load_state_dict(state_dict)
             print('loading checkpoint from: {}'.format(checkpoint_file_path))
 
@@ -54,7 +59,7 @@ def __init__(self, args):
                 args.pretrain_checkpoint_file_name)
             state_dict = torch.load(
                 checkpoint_file_path,
-                map_location='cuda:{}'.format(args.gpu))
+                map_location=map_location)
             self.load_state_dict(state_dict)
             print('loading checkpoint from: {}'.format(checkpoint_file_path))
 
@@ -74,10 +79,10 @@ def forward(self, input_ids, token_type_ids, attention_mask):
         return output_dict, score
 
     @torch.no_grad()
-    def get_score(self, sample: dict):
+    def get_score(self, context: List[str], response: str):
         self.eval()
         input_ids, token_type_ids, attention_mask = self.encode_ctx_res_pair(
-            sample['context'], sample['hyp_response'])
+            context, response)
         _, score = self.forward(input_ids, token_type_ids, attention_mask)
         return score[0].item()