diff --git a/.flake8 b/.flake8
index b8f0e4715..19c3a9bd6 100644
--- a/.flake8
+++ b/.flake8
@@ -5,6 +5,7 @@ max-line-length = 80
 per-file-ignores =
     # line too long
     egs/librispeech/ASR/*/conformer.py: E501,
+    egs/aishell/ASR/*/conformer.py: E501,
 
 exclude =
   .git,
diff --git a/egs/aishell/ASR/local/compute_fbank_aishell.py b/egs/aishell/ASR/local/compute_fbank_aishell.py
index d170931db..df696dbf5 100755
--- a/egs/aishell/ASR/local/compute_fbank_aishell.py
+++ b/egs/aishell/ASR/local/compute_fbank_aishell.py
@@ -107,4 +107,3 @@ if __name__ == "__main__":
 
     args = get_args()
     compute_fbank_aishell(num_mel_bins=args.num_mel_bins)
-
diff --git a/egs/aishell/ASR/local/compute_fbank_musan.py b/egs/aishell/ASR/local/compute_fbank_musan.py
index 4b0120283..0a5d82ccb 100755
--- a/egs/aishell/ASR/local/compute_fbank_musan.py
+++ b/egs/aishell/ASR/local/compute_fbank_musan.py
@@ -87,6 +87,7 @@ def compute_fbank_musan(num_mel_bins: int = 80):
         )
         musan_cuts.to_json(musan_cuts_path)
 
+
 def get_args():
     parser = argparse.ArgumentParser()
     parser.add_argument(
diff --git a/egs/aishell/ASR/local/prepare_char.py b/egs/aishell/ASR/local/prepare_char.py
index 5b4ec323d..421b1c3d6 100755
--- a/egs/aishell/ASR/local/prepare_char.py
+++ b/egs/aishell/ASR/local/prepare_char.py
@@ -33,10 +33,9 @@ and generates the following files in the directory `lang_dir`:
     - tokens.txt
 """
 
-import argparse
 import re
 from pathlib import Path
-from typing import Dict, List, Tuple
+from typing import Dict, List
 
 import k2
 import torch
diff --git a/icefall/decode.py b/icefall/decode.py
index 8bf4460d4..4c2a8e01b 100644
--- a/icefall/decode.py
+++ b/icefall/decode.py
@@ -903,4 +903,3 @@ def rescore_with_attention_decoder(
             key = f"ngram_lm_scale_{n_scale}_attention_scale_{a_scale}"
             ans[key] = best_path
     return ans
-