diff --git a/layers/box_utils.py b/layers/box_utils.py
index 84214947b..bea7bfc96 100644
--- a/layers/box_utils.py
+++ b/layers/box_utils.py
@@ -186,7 +186,7 @@ def nms(boxes, scores, overlap=0.5, top_k=200):
 
     keep = scores.new(scores.size(0)).zero_().long()
     if boxes.numel() == 0:
-        return keep
+        return keep, 0
     x1 = boxes[:, 0]
     y1 = boxes[:, 1]
     x2 = boxes[:, 2]
diff --git a/layers/functions/detection.py b/layers/functions/detection.py
index 0d1ef8d30..2c26eeceb 100644
--- a/layers/functions/detection.py
+++ b/layers/functions/detection.py
@@ -52,6 +52,8 @@ def forward(self, loc_data, conf_data, prior_data):
                 boxes = decoded_boxes[l_mask].view(-1, 4)
                 # idx of highest scoring and non-overlapping boxes per class
                 ids, count = nms(boxes, scores, self.nms_thresh, self.top_k)
+                if count == 0:
+                    continue
                 output[i, cl, :count] = \
                     torch.cat((scores[ids[:count]].unsqueeze(1),
                                boxes[ids[:count]]), 1)