diff --git a/pytorch3d/implicitron/dataset/json_index_dataset.py b/pytorch3d/implicitron/dataset/json_index_dataset.py
index 6b3d7102..54a5cd3c 100644
--- a/pytorch3d/implicitron/dataset/json_index_dataset.py
+++ b/pytorch3d/implicitron/dataset/json_index_dataset.py
@@ -422,17 +422,15 @@ class JsonIndexDataset(DatasetBase, ReplaceableBase):
             bbox_xywh = torch.tensor(_get_bbox_from_mask(mask, self.box_crop_mask_thr))
 
             if self.box_crop:
-                clamp_bbox_xyxy = _get_clamp_bbox(
-                    bbox_xywh,
-                    image_path=entry.image.path,
-                    box_crop_context=self.box_crop_context,
-                )
-
-                crop_box_xyxy = _clamp_box_to_image_bounds_and_round(
-                    clamp_bbox_xyxy,
+                clamp_bbox_xyxy = _clamp_box_to_image_bounds_and_round(
+                    _get_clamp_bbox(
+                        bbox_xywh,
+                        image_path=entry.image.path,
+                        box_crop_context=self.box_crop_context,
+                    ),
                     image_size_hw=tuple(mask.shape[-2:]),
                 )
-                crop_box_xywh = _bbox_xyxy_to_xywh(crop_box_xyxy)
+                crop_box_xywh = _bbox_xyxy_to_xywh(clamp_bbox_xyxy)
 
                 mask = _crop_around_box(mask, clamp_bbox_xyxy, full_path)
 
@@ -926,9 +924,10 @@ def _clamp_box_to_image_bounds_and_round(
     image_size_hw: Tuple[int, int],
 ) -> torch.LongTensor:
     bbox_xyxy = bbox_xyxy.clone()
-    bbox_xyxy[[0, 2]] = torch.clamp(bbox_xyxy[[0, 2]], 0.0, image_size_hw[-1])
-    bbox_xyxy[[1, 3]] = torch.clamp(bbox_xyxy[[1, 3]], 0.0, image_size_hw[-2])
-    bbox_xyxy = bbox_xyxy.round().long()
+    bbox_xyxy[[0, 2]] = torch.clamp(bbox_xyxy[[0, 2]], 0, image_size_hw[-1])
+    bbox_xyxy[[1, 3]] = torch.clamp(bbox_xyxy[[1, 3]], 0, image_size_hw[-2])
+    if not isinstance(bbox_xyxy, torch.LongTensor):
+        bbox_xyxy = bbox_xyxy.round().long()
     return bbox_xyxy  # pyre-ignore [7]