diff --git a/torch_struct/semirings/semirings.py b/torch_struct/semirings/semirings.py
index cfc2311..6db6f4c 100644
--- a/torch_struct/semirings/semirings.py
+++ b/torch_struct/semirings/semirings.py
@@ -49,6 +49,7 @@ def dot(cls, a, b):
 
     @staticmethod
     def fill(c, mask, v):
+        mask = mask.to(c.device)
         return torch.where(
             mask, v.type_as(c).view((-1,) + (1,) * (len(c.shape) - 1)), c
         )