diff --git a/ldm/models/diffusion/ddim.py b/ldm/models/diffusion/ddim.py
index 2ebaeabd22..065b32986a 100644
--- a/ldm/models/diffusion/ddim.py
+++ b/ldm/models/diffusion/ddim.py
@@ -17,6 +17,9 @@ class DDIMSampler(object):
         self.schedule = schedule
 
     def register_buffer(self, name, attr):
+        if type(attr) == torch.Tensor:
+            if attr.device != torch.device("cuda"):
+                attr = attr.to(torch.device("cuda"))
         setattr(self, name, attr)
 
     def make_schedule(self, ddim_num_steps, ddim_discretize="uniform", ddim_eta=0., verbose=True):