diff --git a/utils/utils.py b/utils/utils.py
index 6ffdfee8..6abd2b30 100755
--- a/utils/utils.py
+++ b/utils/utils.py
@@ -459,7 +459,7 @@ def build_targets(model, targets):
     return tcls, tbox, indices, av
 
 
-def non_max_suppression(prediction, conf_thres=0.5, nms_thres=0.5, multi_cls=False, method='vision'):
+def non_max_suppression(prediction, conf_thres=0.5, nms_thres=0.5, multi_cls=True, method='vision'):
     """
     Removes detections with lower object confidence score than 'conf_thres'
     Non-Maximum Suppression to further filter detections.
@@ -489,7 +489,7 @@ def non_max_suppression(prediction, conf_thres=0.5, nms_thres=0.5, multi_cls=Fal
         pred[:, :4] = xywh2xyxy(pred[:, :4])
 
         # Multi-class
-        if multi_cls:
+        if multi_cls or conf_thres < 0.01:
             i, j = (pred[:, 4:] > conf_thres).nonzero().t()
             pred = torch.cat((pred[i, :4], pred[i, j + 4].unsqueeze(1), j.float().unsqueeze(1)), 1)
         else:  # best class only