diff --git a/detectron.py b/detectron.py
index f15d566..cf5b879 100644
--- a/detectron.py
+++ b/detectron.py
@@ -54,7 +54,7 @@ class Detectron2(NNOperator):
         # Detectron2 uses BGR-formatted images
         res = self._predictor(image[:,:,::-1])
         res = res['instances']
-        boxes = res.get('pred_boxes').tensor.numpy()
+        boxes = res.get('pred_boxes').tensor.cpu().numpy()
         classes = res.get('pred_classes').numpy()
         scores = res.get('scores').numpy()