diff --git a/src/reco.py b/src/reco.py
index 31a4fe47..db117f0c 100644
--- a/src/reco.py
+++ b/src/reco.py
@@ -23,7 +23,7 @@ def main(args):
     col = get_mongo_collection(col_name, db_name, mongo_uri)
     batch_size = int(args.batch_size)
     source = args.source
-    channels = args.channels
+    channels = int(args.channels)
     waves = get_wav_list(col, batch_size, source)
     uris = [w for w in waves]
     uris = list(map(lambda x: dict(x, **{'channels': channels}), uris))