diff --git a/.flake8 b/.flake8
index 3f1227b9b..b8f0e4715 100644
--- a/.flake8
+++ b/.flake8
@@ -4,8 +4,9 @@ statistics=true
 max-line-length = 80
 per-file-ignores =
     # line too long
-    egs/librispeech/ASR/conformer_ctc/conformer.py: E501,
+    egs/librispeech/ASR/*/conformer.py: E501,
 
 exclude =
   .git,
-  **/data/**
+  **/data/**,
+  icefall/shared/make_kn_lm.py
diff --git a/egs/librispeech/ASR/conformer_mmi/train-with-attention.py b/egs/librispeech/ASR/conformer_mmi/train-with-attention.py
index a3e266814..8b8994059 100755
--- a/egs/librispeech/ASR/conformer_mmi/train-with-attention.py
+++ b/egs/librispeech/ASR/conformer_mmi/train-with-attention.py
@@ -203,7 +203,8 @@ def get_params() -> AttributeDict:
             "warm_step": 80000,
             "use_pruned_intersect": False,
             "den_scale": 1.0,
-            "use_ali_until": 13000,  # use alignments before this number of batches
+            # use alignments before this number of batches
+            "use_ali_until": 13000,
         }
     )
 
diff --git a/egs/librispeech/ASR/conformer_mmi/train.py b/egs/librispeech/ASR/conformer_mmi/train.py
index 18cc80a9a..6580792ff 100755
--- a/egs/librispeech/ASR/conformer_mmi/train.py
+++ b/egs/librispeech/ASR/conformer_mmi/train.py
@@ -203,7 +203,8 @@ def get_params() -> AttributeDict:
             "warm_step": 80000,
             "use_pruned_intersect": False,
             "den_scale": 1.0,
-            "use_ali_until": 13000,  # use alignments before this number of batches
+            # use alignments before this number of batches
+            "use_ali_until": 13000,
         }
     )
 
diff --git a/test/test_lexicon.py b/test/test_lexicon.py
index 2a16db226..69867efc7 100755
--- a/test/test_lexicon.py
+++ b/test/test_lexicon.py
@@ -26,8 +26,8 @@ import os
 import shutil
 import sys
 from pathlib import Path
+from typing import List
 
-import k2
 import sentencepiece as spm
 
 from icefall.lexicon import UniqLexicon