diff --git a/layers/modules/multibox_loss.py b/layers/modules/multibox_loss.py
index fb49cf439..40436de12 100644
--- a/layers/modules/multibox_loss.py
+++ b/layers/modules/multibox_loss.py
@@ -32,8 +32,10 @@ class MultiBoxLoss(nn.Module):
 
     def __init__(self, num_classes, overlap_thresh, prior_for_matching,
                  bkg_label, neg_mining, neg_pos, neg_overlap, encode_target,
-                 use_gpu=True):
+                 use_gpu=None):
         super(MultiBoxLoss, self).__init__()
+        if use_gpu is None:
+            use_gpu = torch.cuda.is_available()
         self.use_gpu = use_gpu
         self.num_classes = num_classes
         self.threshold = overlap_thresh