diff --git a/egs/multi_zh-hans/ASR/local/prepare_lm_training_data.py b/egs/multi_zh-hans/ASR/local/prepare_lm_training_data.py
index e931086fb..41638cd82 100755
--- a/egs/multi_zh-hans/ASR/local/prepare_lm_training_data.py
+++ b/egs/multi_zh-hans/ASR/local/prepare_lm_training_data.py
@@ -99,9 +99,9 @@ def main():
     with open(args.lm_data) as f:
         while True:
             line = f.readline()
-            line = tokenize_by_CJK_char(line)
             if line == "":
                 break
+            line = tokenize_by_CJK_char(line)
 
             if step and processed % step == 0:
                 logging.info(f"Processed number of lines: {processed} ")