diff --git a/data.py b/data.py
index e0e9f06..a84e1ef 100644
--- a/data.py
+++ b/data.py
@@ -39,7 +39,7 @@ def next_crop(self, for_g, idx):
         """Return a crop according to the pre-determined list of indices. Noise is added to crops for D"""
         size = self.g_input_shape if for_g else self.d_input_shape
         top, left = self.get_top_left(size, for_g, idx)
-        crop_im = self.input_image[top:top + size, left:left + size, :]
+        crop_im = self.input_image[top:top + size, left:left + size, :].copy()
         if not for_g:  # Add noise to the image for d
             crop_im += np.random.randn(*crop_im.shape) / 255.0
         return im2tensor(crop_im)
@@ -77,4 +77,4 @@ def get_top_left(self, size, for_g, idx):
         row, col = int(center / self.in_cols), center % self.in_cols
         top, left = min(max(0, row - size // 2), self.in_rows - size), min(max(0, col - size // 2), self.in_cols - size)
         # Choose even indices (to avoid misalignment with the loss map for_g)
-        return top - top % 2, left - left % 2
\ No newline at end of file
+        return top - top % 2, left - left % 2