diff --git a/utils/utils.py b/utils/utils.py
index 57d16b36..40ab7c68 100755
--- a/utils/utils.py
+++ b/utils/utils.py
@@ -332,16 +332,25 @@ def build_targets(model, targets):
 
         # iou of targets-anchors
         t, a = targets, []
-        gwh = targets[:, 4:6] * layer.ng
+        gwh = t[:, 4:6] * layer.ng
         if nt:
-            iou = [wh_iou(x, gwh) for x in layer.anchor_vec]
-            iou, a = torch.stack(iou, 0).max(0)  # best iou and anchor
+            iou = torch.stack([wh_iou(x, gwh) for x in layer.anchor_vec], 0)
+
+            use_best = True
+            if use_best:
+                iou, a = iou.max(0)  # best iou and anchor
+            else:
+                na = len(layer.anchor_vec)  # number of anchors
+                a = torch.arange(na).view((-1, 1)).repeat([1, nt]).view(-1)
+                t = targets.repeat([na, 1])
+                gwh = gwh.repeat([na, 1])
+                iou = iou.view(-1)  # use all ious
 
             # reject below threshold ious (OPTIONAL, increases P, lowers R)
             reject = True
             if reject:
                 j = iou > iou_thres
-                t, a, gwh = targets[j], a[j], gwh[j]
+                t, a, gwh = t[j], a[j], gwh[j]
 
         # Indices
         b, c = t[:, :2].long().t()  # target image, class