diff --git a/examples/aishell/asr3/conf/wav2vec2ASR_adadelta.yaml b/examples/aishell/asr3/conf/wav2vec2ASR_adadelta.yaml
index cdb04f8c1..ec287f0c6 100755
--- a/examples/aishell/asr3/conf/wav2vec2ASR_adadelta.yaml
+++ b/examples/aishell/asr3/conf/wav2vec2ASR_adadelta.yaml
@@ -107,6 +107,7 @@ vocab_filepath: data/lang_char/vocab.txt
 ###########################################
 
 unit_type: 'char'
+tokenizer: bert-base-chinese
 mean_std_filepath: 
 preprocess_config: conf/preprocess.yaml
 sortagrad: -1 # Feed samples from shortest to longest ; -1: enabled for all epochs, 0: disabled, other: enabled for 'other' epochs