diff --git a/make_win_usb b/make_win_usb
index 7bb6b22..5bdf4c0 100755
--- a/make_win_usb
+++ b/make_win_usb
@@ -6,6 +6,7 @@ WIN_USB="${1}"
 WIN_USB_MNT_PATH=/mnt/USBW7/
 WIN_ISO_FILE="${2}"
 WIN_ISO_MNT_PATH=/mnt/WIN7/
+MS_SYS_VERSION="2.5.1"
 
 # Test if args exists
 for file in "${WIN_USB}" "${WIN_ISO_FILE}"; do
@@ -51,12 +52,12 @@ sudo aptitude install -y gettext
 # Ensure to download the last version of ms-sys
 if [ ! $(command -v ms-sys) ]; then
   # http://ms-sys.sourceforge.net/#Download
-  wget http://netix.dl.sourceforge.net/project/ms-sys/ms-sys%20development/2.5.0/ms-sys-2.5.0.tar.gz -O /tmp/ms-sys-2.5.0.tar.gz
+  wget http://netix.dl.sourceforge.net/project/ms-sys/ms-sys%20development/"${MS_SYS_VERSION}"/ms-sys-"${MS_SYS_VERSION}".tar.gz -O /tmp/ms-sys-"${MS_SYS_VERSION}".tar.gz
 
   # Extract and install ms-sys
   cd /tmp
-  tar xzvf /tmp/ms-sys-2.5.0.tar.gz
-  cd /tmp/ms-sys-2.5.0.tar.gz
+  tar xzvf /tmp/ms-sys-"${MS_SYS_VERSION}".tar.gz
+  cd /tmp/ms-sys-"${MS_SYS_VERSION}".tar.gz
   sudo make
   sudo make install
 fi