diff --git a/train.py b/train.py
index 3c113289..43a0465d 100644
--- a/train.py
+++ b/train.py
@@ -221,7 +221,7 @@ def train():
 
         # Prebias
         if prebias:
-            if epoch < 3:  # prebias
+            if epoch < 1:  # prebias
                 ps = 0.1, 0.9  # prebias settings (lr=0.1, momentum=0.9)
             else:  # normal training
                 ps = hyp['lr0'], hyp['momentum']  # normal training settings
@@ -278,7 +278,7 @@ def train():
             pred = model(imgs)
 
             # Compute loss
-            loss, loss_items = compute_loss(pred, targets, model)
+            loss, loss_items = compute_loss(pred, targets, model, not prebias)
             if not torch.isfinite(loss):
                 print('WARNING: non-finite loss, ending training ', loss_items)
                 return results
diff --git a/utils/utils.py b/utils/utils.py
index 0b81fcec..b53fa9d7 100755
--- a/utils/utils.py
+++ b/utils/utils.py
@@ -361,7 +361,7 @@ class FocalLoss(nn.Module):
             return loss
 
 
-def compute_loss(p, targets, model):  # predictions, targets, model
+def compute_loss(p, targets, model, giou_flag=True):  # predictions, targets, model
     ft = torch.cuda.FloatTensor if p[0].is_cuda else torch.Tensor
     lcls, lbox, lobj = ft([0]), ft([0]), ft([0])
     tcls, tbox, indices, anchor_vec = build_targets(model, targets)
@@ -399,7 +399,7 @@ def compute_loss(p, targets, model):  # predictions, targets, model
             pbox = torch.cat((pxy, pwh), 1)  # predicted box
             giou = bbox_iou(pbox.t(), tbox[i], x1y1x2y2=False, GIoU=True)  # giou computation
             lbox += (1.0 - giou).sum() if red == 'sum' else (1.0 - giou).mean()  # giou loss
-            tobj[b, a, gj, gi] = giou.detach().type(tobj.dtype)
+            tobj[b, a, gj, gi] = giou.detach().type(tobj.dtype) if giou_flag else 1.0
 
             if 'default' in arc and model.nc > 1:  # cls loss (only if multiple classes)
                 t = torch.zeros_like(ps[:, 5:])  # targets