diff --git a/upgradeTetrasBack.sh b/upgradeTetrasBack.sh
index 39d32c22ac27f0110cc2ab672335650c4d981cce..b257d88044965eb18abe0c138759fa92c876cdb1 100644
--- a/upgradeTetrasBack.sh
+++ b/upgradeTetrasBack.sh
@@ -16,8 +16,8 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-OLD=`pwd`
-DIR=$DIR
+OLD=$PWD
+DIR="$OLD/Tetras-back"
 if [ ! -d $DIR ]
 then
     echo "Tetras-back not installed, aborting"