diff --git a/.flake8 b/.flake8
index 3f1227b9b..b2bbb0a44 100644
--- a/.flake8
+++ b/.flake8
@@ -5,6 +5,7 @@ max-line-length = 80
 per-file-ignores =
     # line too long
     egs/librispeech/ASR/conformer_ctc/conformer.py: E501,
+    egs/librispeech/ASR/conformer_ctc/decode.py: E501,
 
 exclude =
   .git,
diff --git a/egs/librispeech/ASR/tdnn_lstm_ctc/decode.py b/egs/librispeech/ASR/tdnn_lstm_ctc/decode.py
index f4a3dea12..26946e0d0 100755
--- a/egs/librispeech/ASR/tdnn_lstm_ctc/decode.py
+++ b/egs/librispeech/ASR/tdnn_lstm_ctc/decode.py
@@ -43,6 +43,7 @@ from icefall.utils import (
     setup_logger,
     store_transcripts,
     write_error_stats,
+    str2bool,
 )
 
 
diff --git a/egs/librispeech/ASR/tdnn_lstm_ctc/pretrained.py b/egs/librispeech/ASR/tdnn_lstm_ctc/pretrained.py
index a08c8bab2..4f82a989c 100644
--- a/egs/librispeech/ASR/tdnn_lstm_ctc/pretrained.py
+++ b/egs/librispeech/ASR/tdnn_lstm_ctc/pretrained.py
@@ -219,7 +219,7 @@ def main():
         features, batch_first=True, padding_value=math.log(1e-10)
     )
     features = features.permute(0, 2, 1)  # now features is [N, C, T]
-    
+
     with torch.no_grad():
         nnet_output = model(features)
         # nnet_output is [N, T, C]