diff --git a/configs/rec/rec_mtb_nrtr.yml b/configs/rec/rec_mtb_nrtr.yml
index c832b9170cc3f990656df742f908db39ff0bdaea..171ac7e3f5fd562d0af842bdde9d9a1df0bc90b2 100644
--- a/configs/rec/rec_mtb_nrtr.yml
+++ b/configs/rec/rec_mtb_nrtr.yml
@@ -46,7 +46,7 @@ Architecture:
     name: TransformerOptim
     d_model: 512
     num_encoder_layers: 6
-    beam_size: -1    # When Beam size is greater than 0, it means to use beam search when evaluation.
+    beam_size: 10    # When Beam size is greater than 0, it means to use beam search when evaluation.
     
 
 Loss: