diff --git a/python/obitools3/commands/build_ref_db.pyx b/python/obitools3/commands/build_ref_db.pyx
index 3c4074d..618538c 100755
--- a/python/obitools3/commands/build_ref_db.pyx
+++ b/python/obitools3/commands/build_ref_db.pyx
@@ -31,10 +31,9 @@ def addOptions(parser):
     group.add_argument('--threshold','-t',
                       action="store", dest="build_ref_db:threshold",
                       metavar='<THRESHOLD>',
-                      default=0.0,
+                      default=0.99,
                       type=float,
-                      help="Score threshold as a normalized identity, e.g. 0.95 for an identity of 95%%. Default: 0.00"
-                           " (no threshold).")
+                      help="Score threshold as a normalized identity, e.g. 0.95 for an identity of 95%%. Default: 0.99.")
 
 
 def run(config):