diff --git a/codes/data/full_image_dataset.py b/codes/data/full_image_dataset.py
index e4f297ab..2ba9b1e2 100644
--- a/codes/data/full_image_dataset.py
+++ b/codes/data/full_image_dataset.py
@@ -219,7 +219,7 @@ class FullImageDataset(data.Dataset):
             img_GT, gt_fullsize_ref, gt_mask, gt_center = self.pull_tile(img_full)
         else:
             img_GT, gt_fullsize_ref = img_full, img_full
-            gt_mask = np.ones(img_full.shape[:2])
+            gt_mask = np.ones(img_full.shape[:2], dtype=gt_fullsize_ref.dtype)
             gt_center = torch.tensor([img_full.shape[0] // 2, img_full.shape[1] // 2], dtype=torch.long)
         orig_gt_dim = gt_fullsize_ref.shape[:2]