diff --git a/src/beignet/datasets/_fasta_dataset.py b/src/beignet/datasets/_fasta_dataset.py
index e3d93ebe6f..b9cffa9cdf 100644
--- a/src/beignet/datasets/_fasta_dataset.py
+++ b/src/beignet/datasets/_fasta_dataset.py
@@ -30,7 +30,7 @@ def __init__(
 
         self.data = ThreadSafeFile(self.root, open)
 
-        offsets = Path(f"{self.root}.index.npy")
+        offsets = Path(f"{self.root}.offsets.npy")
 
         if offsets.exists():
             self.offsets, sizes = numpy.load(f"{offsets}")