diff --git a/lcnn/models/line_vectorizer.py b/lcnn/models/line_vectorizer.py
index a40e922..b6a6eff 100644
--- a/lcnn/models/line_vectorizer.py
+++ b/lcnn/models/line_vectorizer.py
@@ -171,7 +171,7 @@ def sample_lines(self, meta, jmap, joff, mode):
 
             # index: [N_TYPE, K]
             score, index = torch.topk(jmap, k=K)
-            y = (index / 128).float() + torch.gather(joff[:, 0], 1, index) + 0.5
+            y = (index // 128).float() + torch.gather(joff[:, 0], 1, index) + 0.5
             x = (index % 128).float() + torch.gather(joff[:, 1], 1, index) + 0.5
 
             # xy: [N_TYPE, K, 2]