diff --git a/rfdiffusion/inference/model_runners.py b/rfdiffusion/inference/model_runners.py
index 9a33d98d..ec3b27b4 100644
--- a/rfdiffusion/inference/model_runners.py
+++ b/rfdiffusion/inference/model_runners.py
@@ -304,7 +304,7 @@ def sample_init(self, return_forward_trajectory=False):
 
         xyz_27 = self.target_feats['xyz_27']
         mask_27 = self.target_feats['mask_27']
-        seq_orig = self.target_feats['seq']
+        seq_orig = self.target_feats['seq'].long()
         L_mapped = len(self.contig_map.ref)
         contig_map=self.contig_map