diff --git a/nixos/modules/services/networking/softether.nix b/nixos/modules/services/networking/softether.nix
index 16530078b978..9087b75c29c1 100644
--- a/nixos/modules/services/networking/softether.nix
+++ b/nixos/modules/services/networking/softether.nix
@@ -3,7 +3,6 @@
 with lib;
 
 let
-  pkg = pkgs.softether;
   cfg = config.services.softether;
 
 in
@@ -17,6 +16,15 @@ in
 
       enable = mkEnableOption "SoftEther VPN services";
 
+      package = mkOption {
+        type = types.package;
+        default = pkgs.softether;
+        defaultText = "pkgs.softether";
+        description = ''
+          softether derivation to use.
+        '';
+      };
+
       vpnserver.enable = mkEnableOption "SoftEther VPN Server";
 
       vpnbridge.enable = mkEnableOption "SoftEther VPN Bridge";
@@ -41,7 +49,7 @@ in
 
       dataDir = mkOption {
         type = types.string;
-        default = "${pkg.dataDir}";
+        default = "${cfg.package.dataDir}";
         description = ''
           Data directory for SoftEther VPN.
         '';
@@ -57,12 +65,13 @@ in
 
     mkMerge [{
       environment.systemPackages = [
-          (pkgs.lib.overrideDerivation pkg (attrs: {
+          (pkgs.lib.overrideDerivation cfg.package (attrs: {
             dataDir = cfg.dataDir;
           }))
         ];
       systemd.services."softether-init" = {
         description = "SoftEther VPN services initial task";
+        wantedBy = [ "network.target" ];
         serviceConfig = {
           Type = "oneshot";
           RemainAfterExit = false;
@@ -71,11 +80,11 @@ in
             for d in vpnserver vpnbridge vpnclient vpncmd; do
                 if ! test -e ${cfg.dataDir}/$d; then
                     ${pkgs.coreutils}/bin/mkdir -m0700 -p ${cfg.dataDir}/$d
-                    install -m0600 ${pkg}${cfg.dataDir}/$d/hamcore.se2 ${cfg.dataDir}/$d/hamcore.se2
+                    install -m0600 ${cfg.package}${cfg.dataDir}/$d/hamcore.se2 ${cfg.dataDir}/$d/hamcore.se2
                 fi
             done
             rm -rf ${cfg.dataDir}/vpncmd/vpncmd
-            ln -s ${pkg}${cfg.dataDir}/vpncmd/vpncmd ${cfg.dataDir}/vpncmd/vpncmd
+            ln -s ${cfg.package}${cfg.dataDir}/vpncmd/vpncmd ${cfg.dataDir}/vpncmd/vpncmd
         '';
       };
     }
@@ -83,17 +92,17 @@ in
     (mkIf (cfg.vpnserver.enable) {
       systemd.services.vpnserver = {
         description = "SoftEther VPN Server";
-        after = [ "softether-init.service" "network.target" ];
-        wants = [ "softether-init.service" ];
-        wantedBy = [ "multi-user.target" ];
+        after = [ "softether-init.service" ];
+        requires = [ "softether-init.service" ];
+        wantedBy = [ "network.target" ];
         serviceConfig = {
           Type = "forking";
-          ExecStart = "${pkg}/bin/vpnserver start";
-          ExecStop = "${pkg}/bin/vpnserver stop";
+          ExecStart = "${cfg.package}/bin/vpnserver start";
+          ExecStop = "${cfg.package}/bin/vpnserver stop";
         };
         preStart = ''
             rm -rf ${cfg.dataDir}/vpnserver/vpnserver
-            ln -s ${pkg}${cfg.dataDir}/vpnserver/vpnserver ${cfg.dataDir}/vpnserver/vpnserver
+            ln -s ${cfg.package}${cfg.dataDir}/vpnserver/vpnserver ${cfg.dataDir}/vpnserver/vpnserver
         '';
         postStop = ''
             rm -rf ${cfg.dataDir}/vpnserver/vpnserver
@@ -104,17 +113,17 @@ in
     (mkIf (cfg.vpnbridge.enable) {
       systemd.services.vpnbridge = {
         description = "SoftEther VPN Bridge";
-        after = [ "softether-init.service" "network.target" ];
-        wants = [ "softether-init.service" ];
-        wantedBy = [ "multi-user.target" ];
+        after = [ "softether-init.service" ];
+        requires = [ "softether-init.service" ];
+        wantedBy = [ "network.target" ];
         serviceConfig = {
           Type = "forking";
-          ExecStart = "${pkg}/bin/vpnbridge start";
-          ExecStop = "${pkg}/bin/vpnbridge stop";
+          ExecStart = "${cfg.package}/bin/vpnbridge start";
+          ExecStop = "${cfg.package}/bin/vpnbridge stop";
         };
         preStart = ''
             rm -rf ${cfg.dataDir}/vpnbridge/vpnbridge
-            ln -s ${pkg}${cfg.dataDir}/vpnbridge/vpnbridge ${cfg.dataDir}/vpnbridge/vpnbridge
+            ln -s ${cfg.package}${cfg.dataDir}/vpnbridge/vpnbridge ${cfg.dataDir}/vpnbridge/vpnbridge
         '';
         postStop = ''
             rm -rf ${cfg.dataDir}/vpnbridge/vpnbridge
@@ -125,17 +134,17 @@ in
     (mkIf (cfg.vpnclient.enable) {
       systemd.services.vpnclient = {
         description = "SoftEther VPN Client";
-        after = [ "softether-init.service" "network.target" ];
-        wants = [ "softether-init.service" ];
-        wantedBy = [ "multi-user.target" ];
+        after = [ "softether-init.service" ];
+        requires = [ "softether-init.service" ];
+        wantedBy = [ "network.target" ];
         serviceConfig = {
           Type = "forking";
-          ExecStart = "${pkg}/bin/vpnclient start";
-          ExecStop = "${pkg}/bin/vpnclient stop";
+          ExecStart = "${cfg.package}/bin/vpnclient start";
+          ExecStop = "${cfg.package}/bin/vpnclient stop";
         };
         preStart = ''
             rm -rf ${cfg.dataDir}/vpnclient/vpnclient
-            ln -s ${pkg}${cfg.dataDir}/vpnclient/vpnclient ${cfg.dataDir}/vpnclient/vpnclient
+            ln -s ${cfg.package}${cfg.dataDir}/vpnclient/vpnclient ${cfg.dataDir}/vpnclient/vpnclient
         '';
         postStart = ''
             sleep 1
diff --git a/pkgs/servers/softether/4.20.nix b/pkgs/servers/softether/4.20.nix
new file mode 100644
index 000000000000..c6ef5a3a4df2
--- /dev/null
+++ b/pkgs/servers/softether/4.20.nix
@@ -0,0 +1,53 @@
+{ stdenv, fetchurl
+, openssl, readline, ncurses, zlib }:
+
+let
+  os = if stdenv.isLinux then "1"
+       else if stdenv.isFreeBSD then "2"
+       else if stdenv.isSunOS then "3"
+       else if stdenv.isDarwin then "4"
+       else if stdenv.isOpenBSD then "5"
+       else "";
+  cpuBits = if stdenv.is64bit then "2" else "1";
+
+in
+
+stdenv.mkDerivation rec {
+  name = "softether-${version}";
+  version = "4.20";
+  build = "9608";
+  compiledDate = "2016.04.17";
+  dataDir = "/var/lib/softether";
+
+  src = fetchurl {
+    url = "http://www.softether-download.com/files/softether/v${version}-${build}-rtm-${compiledDate}-tree/Source_Code/softether-src-v${version}-${build}-rtm.tar.gz";
+    sha256 = "e559644e34ec6feba43d99f4083f77f9b082dd0574d0bb1e416a65f32ccbc51e";
+  };
+
+  buildInputs = [ openssl readline ncurses zlib ];
+
+  preConfigure = ''
+      echo "${os}
+      ${cpuBits}
+      " | ./configure
+      rm configure
+  '';
+
+  buildPhase = ''
+      mkdir -p $out/bin
+      sed -i \
+          -e "/INSTALL_BINDIR=/s|/usr/bin|/bin|g" \
+          -e "/_DIR=/s|/usr|${dataDir}|g" \
+          -e "s|\$(INSTALL|$out/\$(INSTALL|g" \
+          -e "/echo/s|echo $out/|echo |g" \
+          Makefile
+  '';
+
+  meta = with stdenv.lib; {
+    description = "An Open-Source Free Cross-platform Multi-protocol VPN Program";
+    homepage = https://www.softether.org/;
+    license = licenses.gpl2;
+    maintainers = [ maintainers.rick68 ];
+    platforms = platforms.linux;
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index f971713b166a..f7e19ee1b34c 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -11738,7 +11738,8 @@ with pkgs;
   oracleXE = callPackage ../servers/sql/oracle-xe { };
 
   softether_4_18 = callPackage ../servers/softether/4.18.nix { };
-  softether = softether_4_18;
+  softether_4_20 = callPackage ../servers/softether/4.20.nix { };
+  softether = softether_4_20;
 
   qboot = callPackage ../applications/virtualization/qboot { stdenv = stdenv_32bit; };