diff --git a/egs/csj/s5/local/chain/tuning/run_tdnn_1a.sh b/egs/csj/s5/local/chain/tuning/run_tdnn_1a.sh
index a463db77066..75ceb80e3e0 100755
--- a/egs/csj/s5/local/chain/tuning/run_tdnn_1a.sh
+++ b/egs/csj/s5/local/chain/tuning/run_tdnn_1a.sh
@@ -133,7 +133,7 @@ if [ $stage -le 12 ]; then
   echo "$0: creating neural net configs using the xconfig parser";
 
   num_targets=$(tree-info $tree_dir/tree |grep num-pdfs|awk '{print $2}')
-  learning_rate_factor=$(echo "print 0.5/$xent_regularize" | python)
+  learning_rate_factor=$(echo "print (0.5/$xent_regularize)" | python)
 
   mkdir -p $dir/configs
   cat <<EOF > $dir/configs/network.xconfig