diff --git a/egs/librispeech/ASR/.conv_feat_vis.py.swp b/egs/librispeech/ASR/.conv_feat_vis.py.swp
index 6d061fb99..bb98c8551 100644
Binary files a/egs/librispeech/ASR/.conv_feat_vis.py.swp and b/egs/librispeech/ASR/.conv_feat_vis.py.swp differ
diff --git a/egs/librispeech/ASR/conv_feat_vis.py b/egs/librispeech/ASR/conv_feat_vis.py
index 7b0c130d1..0705c717c 100644
--- a/egs/librispeech/ASR/conv_feat_vis.py
+++ b/egs/librispeech/ASR/conv_feat_vis.py
@@ -16,5 +16,5 @@ feats_all = feats_all.transpose(0,1)
 
 for i in range(512):
     plt.hist(feats_all[i])
-    plt.savefig(f'dim_{i}')
+    plt.savefig(f'dim_{i}.pdf')
     plt.close()