diff --git a/build.sh b/build.sh
index 9b8b737..77fc6aa 100755
--- a/build.sh
+++ b/build.sh
@@ -48,8 +48,7 @@ $cdir/py3/bin/python $cdir/app/fastwhisper.py -w $cdir &
 exit 0
 EOF
 cat > $cdir/stop.sh <<EOF
-PID=\$(lsof -t -i:9925)
-kill -9 \$PID
+kill -9 \$(lsof -t -i:9925)
 EOF
 chmod +x $cdir/start.sh stop.sh
 sudo mkdir /var/log/fastwhisper