diff --git a/configs/7B_MoE4_sft.py b/configs/7B_MoE4_sft.py
index d2ead39..cc94cdc 100644
--- a/configs/7B_MoE4_sft.py
+++ b/configs/7B_MoE4_sft.py
@@ -179,5 +179,5 @@ monitor = dict(
 model_type = "INTERNLM_MoE"
 
 # metric_dtype can be "fp32" or other string
-# only when set to fp32 or unset will use fp32 to calc in metrics
-metric_dtype = "fp32"
+# only when set to "fp32" will use fp32 to calc in metrics
+# metric_dtype = "fp32"
diff --git a/configs/7B_sft.py b/configs/7B_sft.py
index 39a84fc..360ee92 100644
--- a/configs/7B_sft.py
+++ b/configs/7B_sft.py
@@ -179,5 +179,5 @@ monitor = dict(
 )
 
 # metric_dtype can be "fp32" or other string
-# only when set to fp32 or unset will use fp32 to calc in metrics
-metric_dtype = "fp32"
+# only when set to "fp32" will use fp32 to calc in metrics
+# metric_dtype = "fp32"
diff --git a/internlm/model/metrics.py b/internlm/model/metrics.py
index 2846245..704d2d6 100644
--- a/internlm/model/metrics.py
+++ b/internlm/model/metrics.py
@@ -26,8 +26,11 @@ class AccPerplex:
         self.device = device
         self.right = torch.Tensor([0]).to(device=device)
         self.total = torch.Tensor([0]).to(device=device)
-        self.metric_dtype = torch.float if gpc.config.get("metric_dtype", "fp32") == "fp32" else None
-        self.total_log_probs = torch.Tensor([0]).to(device=device, dtype=self.metric_dtype)
+        self.metric_dtype = torch.float if gpc.config.get("metric_dtype", None) == "fp32" else None
+        if self.metric_dtype is not None:
+            self.total_log_probs = torch.Tensor([0]).to(device=device, dtype=self.metric_dtype)
+        else:
+            self.total_log_probs = torch.Tensor([0]).to(device=device)
         self.tp_pg = tp_pg
         self.dp_pg = dp_pg
         self.tp_local_rank = torch.distributed.get_rank(self.tp_pg)