diff --git a/bob/bio/vein/database/verafinger.py b/bob/bio/vein/database/verafinger.py
index 46d35383260e68a2c76cf4684137e5b89fd09099..abc7897526a362696623bdec0c2fda9ab3d3615c 100644
--- a/bob/bio/vein/database/verafinger.py
+++ b/bob/bio/vein/database/verafinger.py
@@ -6,6 +6,7 @@
 from bob.bio.base.database import BioFile, BioDatabase
 
 from . import AnnotatedArray
+from ..preprocessor.utils import poly_to_mask
 
 
 class File(BioFile):