diff --git a/ldm/models/diffusion/ddpm.py b/ldm/models/diffusion/ddpm.py
index 3350c03..ce8c51b 100644
--- a/ldm/models/diffusion/ddpm.py
+++ b/ldm/models/diffusion/ddpm.py
@@ -17,7 +17,10 @@ from functools import partial
 import itertools
 from tqdm import tqdm
 from torchvision.utils import make_grid
-from pytorch_lightning.utilities.distributed import rank_zero_only
+try:
+    from pytorch_lightning.utilities import rank_zero_only
+except:
+    from pytorch_lightning.utilities.distributed import rank_zero_only
 from omegaconf import ListConfig
 
 from ldm.util import log_txt_as_img, exists, default, ismap, isimage, mean_flat, count_params, instantiate_from_config