diff --git a/sam3/model/position_encoding.py b/sam3/model/position_encoding.py
index f38c62b32..9debcee1e 100644
--- a/sam3/model/position_encoding.py
+++ b/sam3/model/position_encoding.py
@@ -52,7 +52,7 @@ def __init__(
                 (precompute_resolution // 32, precompute_resolution // 32),
             ]
             for size in precompute_sizes:
-                tensors = torch.zeros((1, 1) + size, device="cuda")
+                tensors = torch.zeros((1, 1) + size, device="cuda" if torch.cuda.is_available() else "cpu")
                 self.forward(tensors)
                 # further clone and detach it in the cache (just to be safe)
                 self.cache[size] = self.cache[size].clone().detach()