diff --git a/3.New_server_deployment/4.APT_upgrade/0_setup.sh b/3.New_server_deployment/4.APT_upgrade/0_setup.sh
index 501706ce2157d22e9249169eb110752e683e977c..5460a886649a0d42985c3b764926cd51e1e63e83 100755
--- a/3.New_server_deployment/4.APT_upgrade/0_setup.sh
+++ b/3.New_server_deployment/4.APT_upgrade/0_setup.sh
@@ -15,11 +15,11 @@ fi
 # update sources.list
 rm -f /etc/apt/sources.list~
 echo "Updating /etc/apt/sources.list file."
-cp sources16.list /etc/apt/sources.list
+cp sources.list /etc/apt/sources.list
 if ( rgrep '14.04' /etc/lsb-release >/dev/null ); then
-	sed -i 's@xenial@trusty@' /etc/apt/sources.list
-elif ( rgrep '18.04' /etc/lsb-release >/dev/null ); then
-	sed -i 's@xenial@bionic@' /etc/apt/sources.list
+	sed -i 's@bionic@trusty@' /etc/apt/sources.list
+elif ( rgrep '16.04' /etc/lsb-release >/dev/null ); then
+	sed -i 's@bionic@xenial@' /etc/apt/sources.list
 fi
 
 # modify sources.list to use ubicast cache
diff --git a/3.New_server_deployment/4.APT_upgrade/sources.list b/3.New_server_deployment/4.APT_upgrade/sources.list
new file mode 100644
index 0000000000000000000000000000000000000000..06433ad75c9fcca5f3471b4ab6401d8e126a0a51
--- /dev/null
+++ b/3.New_server_deployment/4.APT_upgrade/sources.list
@@ -0,0 +1,4 @@
+deb http://archive.ubuntu.com/ubuntu/ bionic           main restricted universe multiverse
+deb http://archive.ubuntu.com/ubuntu/ bionic-updates   main restricted universe multiverse
+deb http://archive.ubuntu.com/ubuntu/ bionic-backports main restricted universe multiverse
+deb http://security.ubuntu.com/ubuntu bionic-security  main restricted universe multiverse
\ No newline at end of file
diff --git a/3.New_server_deployment/4.APT_upgrade/sources16.list b/3.New_server_deployment/4.APT_upgrade/sources16.list
deleted file mode 100644
index b967902f2f39724ad74c31998b6bb383b9c84818..0000000000000000000000000000000000000000
--- a/3.New_server_deployment/4.APT_upgrade/sources16.list
+++ /dev/null
@@ -1,4 +0,0 @@
-deb http://archive.ubuntu.com/ubuntu/ xenial           main restricted universe multiverse
-deb http://archive.ubuntu.com/ubuntu/ xenial-updates   main restricted universe multiverse
-deb http://archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse
-deb http://security.ubuntu.com/ubuntu xenial-security  main restricted universe multiverse
\ No newline at end of file