diff --git a/egs/wsj/s5/utils/perturb_data_dir_speed.sh b/egs/wsj/s5/utils/perturb_data_dir_speed.sh
index 667bd934f04..a50cdb04be4 100755
--- a/egs/wsj/s5/utils/perturb_data_dir_speed.sh
+++ b/egs/wsj/s5/utils/perturb_data_dir_speed.sh
@@ -2,6 +2,7 @@
 
 # Copyright 2013  Johns Hopkins University (author: Daniel Povey)
 #           2014  Tom Ko
+#           2018  Emotech LTD (author: Pawel Swietojanski)
 # Apache 2.0
 
 # This script operates on a directory, such as in data/train/,
@@ -10,6 +11,8 @@
 #  spk2utt
 #  utt2spk
 #  text
+#  utt2dur
+#  reco2dur
 #
 # It generates the files which are used for perturbing the speed of the original data.
 
@@ -52,6 +55,7 @@ mkdir -p $destdir
 
 cat $srcdir/utt2spk | awk -v p=$utt_prefix '{printf("%s %s%s\n", $1, p, $1);}' > $destdir/utt_map
 cat $srcdir/spk2utt | awk -v p=$spk_prefix '{printf("%s %s%s\n", $1, p, $1);}' > $destdir/spk_map
+cat $srcdir/wav.scp | awk -v p=$spk_prefix '{printf("%s %s%s\n", $1, p, $1);}' > $destdir/reco_map
 if [ ! -f $srcdir/utt2uniq ]; then
   cat $srcdir/utt2spk | awk -v p=$utt_prefix '{printf("%s%s %s\n", p, $1, $1);}' > $destdir/utt2uniq
 else
@@ -65,8 +69,6 @@ cat $srcdir/utt2spk | utils/apply_map.pl -f 1 $destdir/utt_map  | \
 utils/utt2spk_to_spk2utt.pl <$destdir/utt2spk >$destdir/spk2utt
 
 if [ -f $srcdir/segments ]; then
-  # also apply the spk_prefix to the recording-ids.
-  cat $srcdir/wav.scp | awk -v p=$spk_prefix '{printf("%s %s%s\n", $1, p, $1);}' > $destdir/reco_map
 
   utils/apply_map.pl -f 1 $destdir/utt_map <$srcdir/segments | \
     utils/apply_map.pl -f 2 $destdir/reco_map | \
@@ -83,7 +85,6 @@ if [ -f $srcdir/segments ]; then
     utils/apply_map.pl -f 1 $destdir/reco_map <$srcdir/reco2file_and_channel >$destdir/reco2file_and_channel
   fi
 
-  rm $destdir/reco_map 2>/dev/null
 else # no segments->wav indexed by utterance.
   if [ -f $srcdir/wav.scp ]; then
     utils/apply_map.pl -f 1 $destdir/utt_map <$srcdir/wav.scp | sed 's/| *$/ |/' | \
@@ -102,15 +103,23 @@ if [ -f $srcdir/spk2gender ]; then
   utils/apply_map.pl -f 1 $destdir/spk_map <$srcdir/spk2gender >$destdir/spk2gender
 fi
 
+#prepare speed-perturbed utt2dur
 if [ ! -f $srcdir/utt2dur ]; then
   # generate utt2dur if it does not exist in srcdir
   utils/data/get_utt2dur.sh $srcdir
 fi
-
 cat $srcdir/utt2dur | utils/apply_map.pl -f 1 $destdir/utt_map  | \
   awk -v factor=$factor '{print $1, $2/factor;}' >$destdir/utt2dur
 
-rm $destdir/spk_map $destdir/utt_map 2>/dev/null
+#prepare speed-perturbed reco2dur 
+if [ ! -f $srcdir/reco2dur ]; then
+  # generate reco2dur if it does not exist in srcdir
+  utils/data/get_reco2dur.sh $srcdir
+fi
+cat $srcdir/reco2dur | utils/apply_map.pl -f 1 $destdir/reco_map  | \
+  awk -v factor=$factor '{print $1, $2/factor;}' >$destdir/reco2dur
+
+rm $destdir/spk_map $destdir/utt_map $destdir/reco_map 2>/dev/null
 echo "$0: generated speed-perturbed version of data in $srcdir, in $destdir"
 
 utils/validate_data_dir.sh --no-feats --no-text $destdir