diff --git a/vall_e/demo.py b/vall_e/demo.py
index e9d5bb6..a814485 100644
--- a/vall_e/demo.py
+++ b/vall_e/demo.py
@@ -31,14 +31,11 @@ from .config import cfg
 from .data import create_train_dataloader, create_val_dataloader, get_random_prompt
 from .emb.qnt import decode_to_file
 from .metrics import wer, sim_o
-from .utils import setup_logging
+from .utils import setup_logging, mean
 from .utils.io import json_read, json_write
 
 from tqdm import tqdm, trange
 
-def mean( l ):
-	return sum(l) / len(l)
-
 def encode(path):
 	if path is None or not path.exists():
 		return ""
diff --git a/vall_e/models/base_v2.py b/vall_e/models/base_v2.py
index 77e0545..86d4960 100644
--- a/vall_e/models/base_v2.py
+++ b/vall_e/models/base_v2.py
@@ -18,7 +18,7 @@ from torch.utils.checkpoint import checkpoint
 from torchmetrics.classification import BinaryAccuracy, MulticlassAccuracy, MulticlassPrecision
 
 from .arch import *
-from ..utils import ml, clamp
+from ..utils import ml, clamp, mean
 from ..samplers import *
 
 # yuck, kind of needed
@@ -988,9 +988,10 @@ class Base_V2(nn.Module):
 						nll, metrics = _calc_loss( logit, sequence, causal, level )
 						
 						nlls.append( nll )
+						accs.append( accs )
 					
 					nll = sum(nlls)
-					accs = sum(accs) / len(accs)
+					accs = mean(accs)
 
 				if nll is not None:
 					if 'nll' not in loss:
@@ -1003,8 +1004,8 @@ class Base_V2(nn.Module):
 					stats["acc"].append( metrics )
 
 		# average
-		loss = { name: sum( loss[name] ) / len( loss[name] ) for name in loss.keys() }
-		stats = { name: sum( stats[name] ) / len( stats[name] ) for name in stats.keys() }
+		loss = { name: mean( loss[name] ) for name in loss.keys() }
+		stats = { name: mean( stats[name] ) for name in stats.keys() }
 
 		return LossStats(loss, stats)
 
diff --git a/vall_e/utils/__init__.py b/vall_e/utils/__init__.py
index 846d179..e6c03a9 100755
--- a/vall_e/utils/__init__.py
+++ b/vall_e/utils/__init__.py
@@ -16,5 +16,6 @@ from .utils import (
     clamp,
     md5_hash,
     convert_kwargs,
-    coerce_dtype
+    coerce_dtype,
+    mean,
 )
\ No newline at end of file
diff --git a/vall_e/utils/utils.py b/vall_e/utils/utils.py
index a93cfe9..5587bdc 100755
--- a/vall_e/utils/utils.py
+++ b/vall_e/utils/utils.py
@@ -32,6 +32,12 @@ from datetime import datetime
 
 T = TypeVar("T")
 
+def mean( l ):
+	if not l:
+		return 0
+	_l = [ _ for _ in l if _ is not None ]
+	return sum(_l) / len(_l)
+
 # removes prefix from key in a dict
 # useful for mapping args like ar_temperature => temperature
 def convert_kwargs( kwargs, prefix ):