diff --git a/nixos/doc/manual/release-notes/rl-1903.xml b/nixos/doc/manual/release-notes/rl-1903.xml
index eca280afdf1..943b9d2a608 100644
--- a/nixos/doc/manual/release-notes/rl-1903.xml
+++ b/nixos/doc/manual/release-notes/rl-1903.xml
@@ -484,6 +484,13 @@
      the systemd unit configuration from upstream anymore, the unit is completely configured by the NixOS module now.
     </para>
    </listitem>
+   <listitem>
+    <para>
+     New installs of NixOS will default to the Redmine 4.x series unless otherwise specified in
+     <literal>services.redmine.package</literal> while existing installs of NixOS will default to
+     the Redmine 3.x series.
+    </para>
+   </listitem>
   </itemizedlist>
  </section>
 </section>
diff --git a/nixos/modules/services/misc/redmine.nix b/nixos/modules/services/misc/redmine.nix
index d7250c5f35a..98e9c8953c8 100644
--- a/nixos/modules/services/misc/redmine.nix
+++ b/nixos/modules/services/misc/redmine.nix
@@ -61,12 +61,20 @@ in
         description = "Enable the Redmine service.";
       };
 
+      # default to the 4.x series not forcing major version upgrade of those on the 3.x series
       package = mkOption {
         type = types.package;
-        default = pkgs.redmine;
+        default = if versionAtLeast config.system.stateVersion "19.03"
+          then pkgs.redmine_4
+          else pkgs.redmine
+        ;
         defaultText = "pkgs.redmine";
-        description = "Which Redmine package to use.";
-        example = "pkgs.redmine.override { ruby = pkgs.ruby_2_3; }";
+        description = ''
+          Which Redmine package to use. This defaults to version 3.x if
+          <literal>system.stateVersion &lt; 19.03</literal> and version 4.x
+          otherwise.
+        '';
+        example = "pkgs.redmine_4.override { ruby = pkgs.ruby_2_4; }";
       };
 
       user = mkOption {
diff --git a/nixos/tests/redmine.nix b/nixos/tests/redmine.nix
index 330f72854ca..ea72a0121d1 100644
--- a/nixos/tests/redmine.nix
+++ b/nixos/tests/redmine.nix
@@ -1,40 +1,58 @@
-import ./make-test.nix ({ pkgs, lib, ... }:
+{ system ? builtins.currentSystem,
+  config ? {},
+  pkgs ? import ../.. { inherit system config; }
+}:
+
+with import ../lib/testing.nix { inherit system pkgs; };
+with pkgs.lib;
+
+let
+  redmineTest = package: makeTest {
+    machine =
+      { config, pkgs, ... }:
+      { services.mysql.enable = true;
+        services.mysql.package = pkgs.mariadb;
+        services.mysql.ensureDatabases = [ "redmine" ];
+        services.mysql.ensureUsers = [
+          { name = "redmine";
+            ensurePermissions = { "redmine.*" = "ALL PRIVILEGES"; };
+          }
+        ];
+
+        services.redmine.enable = true;
+        services.redmine.package = package;
+        services.redmine.database.socket = "/run/mysqld/mysqld.sock";
+        services.redmine.plugins = {
+          redmine_env_auth = pkgs.fetchurl {
+            url = https://github.com/Intera/redmine_env_auth/archive/0.7.zip;
+            sha256 = "1xb8lyarc7mpi86yflnlgyllh9hfwb9z304f19dx409gqpia99sc";
+          };
+        };
+        services.redmine.themes = {
+          dkuk-redmine_alex_skin = pkgs.fetchurl {
+            url = https://bitbucket.org/dkuk/redmine_alex_skin/get/1842ef675ef3.zip;
+            sha256 = "0hrin9lzyi50k4w2bd2b30vrf1i4fi1c0gyas5801wn8i7kpm9yl";
+          };
+        };
+      };
+
+    testScript = ''
+      startAll;
+
+      $machine->waitForUnit('redmine.service');
+      $machine->waitForOpenPort('3000');
+      $machine->succeed("curl --fail http://localhost:3000/");
+    '';
+  };
+in
 {
-  name = "redmine";
-  meta.maintainers = [ lib.maintainers.aanderse ];
+  redmine_3 = redmineTest pkgs.redmine // {
+    name = "redmine_3";
+    meta.maintainers = [ maintainers.aanderse ];
+  };
 
-  machine =
-    { config, pkgs, ... }:
-    { services.mysql.enable = true;
-      services.mysql.package = pkgs.mariadb;
-      services.mysql.ensureDatabases = [ "redmine" ];
-      services.mysql.ensureUsers = [
-        { name = "redmine";
-          ensurePermissions = { "redmine.*" = "ALL PRIVILEGES"; };
-        }
-      ];
-
-      services.redmine.enable = true;
-      services.redmine.database.socket = "/run/mysqld/mysqld.sock";
-      services.redmine.plugins = {
-        redmine_env_auth = pkgs.fetchurl {
-          url = https://github.com/Intera/redmine_env_auth/archive/0.6.zip;
-          sha256 = "0yyr1yjd8gvvh832wdc8m3xfnhhxzk2pk3gm2psg5w9jdvd6skak";
-        };
-      };
-      services.redmine.themes = {
-        dkuk-redmine_alex_skin = pkgs.fetchurl {
-          url = https://bitbucket.org/dkuk/redmine_alex_skin/get/1842ef675ef3.zip;
-          sha256 = "0hrin9lzyi50k4w2bd2b30vrf1i4fi1c0gyas5801wn8i7kpm9yl";
-        };
-      };
-    };
-
-  testScript = ''
-    startAll;
-
-    $machine->waitForUnit('redmine.service');
-    $machine->waitForOpenPort('3000');
-    $machine->succeed("curl --fail http://localhost:3000/");
-  '';
-})
+  redmine_4 = redmineTest pkgs.redmine_4 // {
+    name = "redmine_4";
+    meta.maintainers = [ maintainers.aanderse ];
+  };
+}
diff --git a/pkgs/applications/version-management/redmine/4.x/Gemfile b/pkgs/applications/version-management/redmine/4.x/Gemfile
new file mode 100644
index 00000000000..3fd176007ab
--- /dev/null
+++ b/pkgs/applications/version-management/redmine/4.x/Gemfile
@@ -0,0 +1,71 @@
+source 'https://rubygems.org'
+
+gem "bundler", ">= 1.5.0"
+
+gem "rails", "5.2.2"
+gem "rouge", "~> 3.3.0"
+gem "request_store", "1.0.5"
+gem "mini_mime", "~> 1.0.1"
+gem "actionpack-xml_parser"
+gem "roadie-rails", "~> 1.3.0"
+gem "mimemagic"
+gem "mail", "~> 2.7.1"
+gem "csv", "~> 3.0.1" if RUBY_VERSION >= "2.3" && RUBY_VERSION < "2.6"
+
+gem "nokogiri", (RUBY_VERSION >= "2.3" ? "~> 1.10.0" : "~> 1.9.1")
+gem "i18n", "~> 0.7.0"
+
+# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
+gem 'tzinfo-data', platforms: [:mingw, :x64_mingw, :mswin]
+gem "rbpdf", "~> 1.19.6"
+
+# Optional gem for LDAP authentication
+group :ldap do
+  gem "net-ldap", "~> 0.16.0"
+end
+
+# Optional gem for OpenID authentication
+group :openid do
+  gem "ruby-openid", "~> 2.3.0", :require => "openid"
+  gem "rack-openid"
+end
+
+platforms :mri, :mingw, :x64_mingw do
+  # Optional gem for exporting the gantt to a PNG file, not supported with jruby
+  group :rmagick do
+    gem "rmagick", ">= 2.14.0"
+  end
+
+  # Optional Markdown support, not for JRuby
+  group :markdown do
+    gem "redcarpet", "~> 3.4.0"
+  end
+end
+
+# Include database gems for the database adapters NixOS supports
+gem "mysql2", "~> 0.5.0", :platforms => [:mri, :mingw, :x64_mingw]
+gem "pg", "~> 1.1.4", :platforms => [:mri, :mingw, :x64_mingw]
+
+group :development do
+  gem "yard"
+end
+
+group :test do
+  gem "rails-dom-testing"
+  gem "mocha"
+  gem "simplecov", "~> 0.14.1", :require => false
+  # For running system tests
+  gem 'puma', '~> 3.7'
+  gem "capybara", '~> 2.13'
+  gem "selenium-webdriver"
+end
+
+local_gemfile = File.join(File.dirname(__FILE__), "Gemfile.local")
+if File.exists?(local_gemfile)
+  eval_gemfile local_gemfile
+end
+
+# Load plugins' Gemfiles
+Dir.glob File.expand_path("../plugins/*/{Gemfile,PluginGemfile}", __FILE__) do |file|
+  eval_gemfile file
+end
diff --git a/pkgs/applications/version-management/redmine/4.x/Gemfile.lock b/pkgs/applications/version-management/redmine/4.x/Gemfile.lock
new file mode 100644
index 00000000000..8c569ddb322
--- /dev/null
+++ b/pkgs/applications/version-management/redmine/4.x/Gemfile.lock
@@ -0,0 +1,204 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    actioncable (5.2.2)
+      actionpack (= 5.2.2)
+      nio4r (~> 2.0)
+      websocket-driver (>= 0.6.1)
+    actionmailer (5.2.2)
+      actionpack (= 5.2.2)
+      actionview (= 5.2.2)
+      activejob (= 5.2.2)
+      mail (~> 2.5, >= 2.5.4)
+      rails-dom-testing (~> 2.0)
+    actionpack (5.2.2)
+      actionview (= 5.2.2)
+      activesupport (= 5.2.2)
+      rack (~> 2.0)
+      rack-test (>= 0.6.3)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.0, >= 1.0.2)
+    actionpack-xml_parser (2.0.1)
+      actionpack (>= 5.0)
+      railties (>= 5.0)
+    actionview (5.2.2)
+      activesupport (= 5.2.2)
+      builder (~> 3.1)
+      erubi (~> 1.4)
+      rails-dom-testing (~> 2.0)
+      rails-html-sanitizer (~> 1.0, >= 1.0.3)
+    activejob (5.2.2)
+      activesupport (= 5.2.2)
+      globalid (>= 0.3.6)
+    activemodel (5.2.2)
+      activesupport (= 5.2.2)
+    activerecord (5.2.2)
+      activemodel (= 5.2.2)
+      activesupport (= 5.2.2)
+      arel (>= 9.0)
+    activestorage (5.2.2)
+      actionpack (= 5.2.2)
+      activerecord (= 5.2.2)
+      marcel (~> 0.3.1)
+    activesupport (5.2.2)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
+      minitest (~> 5.1)
+      tzinfo (~> 1.1)
+    addressable (2.6.0)
+      public_suffix (>= 2.0.2, < 4.0)
+    arel (9.0.0)
+    builder (3.2.3)
+    capybara (2.18.0)
+      addressable
+      mini_mime (>= 0.1.3)
+      nokogiri (>= 1.3.3)
+      rack (>= 1.0.0)
+      rack-test (>= 0.5.4)
+      xpath (>= 2.0, < 4.0)
+    childprocess (0.9.0)
+      ffi (~> 1.0, >= 1.0.11)
+    concurrent-ruby (1.1.4)
+    crass (1.0.4)
+    css_parser (1.6.0)
+      addressable
+    csv (3.0.4)
+    docile (1.1.5)
+    erubi (1.8.0)
+    ffi (1.10.0)
+    globalid (0.4.2)
+      activesupport (>= 4.2.0)
+    htmlentities (4.3.4)
+    i18n (0.7.0)
+    json (2.1.0)
+    loofah (2.2.3)
+      crass (~> 1.0.2)
+      nokogiri (>= 1.5.9)
+    mail (2.7.1)
+      mini_mime (>= 0.1.1)
+    marcel (0.3.3)
+      mimemagic (~> 0.3.2)
+    metaclass (0.0.4)
+    method_source (0.9.2)
+    mimemagic (0.3.3)
+    mini_mime (1.0.1)
+    mini_portile2 (2.4.0)
+    minitest (5.11.3)
+    mocha (1.8.0)
+      metaclass (~> 0.0.1)
+    mysql2 (0.5.2)
+    net-ldap (0.16.1)
+    nio4r (2.3.1)
+    nokogiri (1.10.1)
+      mini_portile2 (~> 2.4.0)
+    pg (1.1.4)
+    public_suffix (3.0.3)
+    puma (3.12.0)
+    rack (2.0.6)
+    rack-openid (1.4.2)
+      rack (>= 1.1.0)
+      ruby-openid (>= 2.1.8)
+    rack-test (1.1.0)
+      rack (>= 1.0, < 3)
+    rails (5.2.2)
+      actioncable (= 5.2.2)
+      actionmailer (= 5.2.2)
+      actionpack (= 5.2.2)
+      actionview (= 5.2.2)
+      activejob (= 5.2.2)
+      activemodel (= 5.2.2)
+      activerecord (= 5.2.2)
+      activestorage (= 5.2.2)
+      activesupport (= 5.2.2)
+      bundler (>= 1.3.0)
+      railties (= 5.2.2)
+      sprockets-rails (>= 2.0.0)
+    rails-dom-testing (2.0.3)
+      activesupport (>= 4.2.0)
+      nokogiri (>= 1.6)
+    rails-html-sanitizer (1.0.4)
+      loofah (~> 2.2, >= 2.2.2)
+    railties (5.2.2)
+      actionpack (= 5.2.2)
+      activesupport (= 5.2.2)
+      method_source
+      rake (>= 0.8.7)
+      thor (>= 0.19.0, < 2.0)
+    rake (12.3.2)
+    rbpdf (1.19.8)
+      htmlentities
+      rbpdf-font (~> 1.19.0)
+    rbpdf-font (1.19.1)
+    redcarpet (3.4.0)
+    request_store (1.0.5)
+    rmagick (2.16.0)
+    roadie (3.4.0)
+      css_parser (~> 1.4)
+      nokogiri (~> 1.5)
+    roadie-rails (1.3.0)
+      railties (>= 3.0, < 5.3)
+      roadie (~> 3.1)
+    rouge (3.3.0)
+    ruby-openid (2.3.0)
+    rubyzip (1.2.2)
+    selenium-webdriver (3.141.0)
+      childprocess (~> 0.5)
+      rubyzip (~> 1.2, >= 1.2.2)
+    simplecov (0.14.1)
+      docile (~> 1.1.0)
+      json (>= 1.8, < 3)
+      simplecov-html (~> 0.10.0)
+    simplecov-html (0.10.2)
+    sprockets (3.7.2)
+      concurrent-ruby (~> 1.0)
+      rack (> 1, < 3)
+    sprockets-rails (3.2.1)
+      actionpack (>= 4.0)
+      activesupport (>= 4.0)
+      sprockets (>= 3.0.0)
+    thor (0.20.3)
+    thread_safe (0.3.6)
+    tzinfo (1.2.5)
+      thread_safe (~> 0.1)
+    websocket-driver (0.7.0)
+      websocket-extensions (>= 0.1.0)
+    websocket-extensions (0.1.3)
+    xpath (3.2.0)
+      nokogiri (~> 1.8)
+    yard (0.9.18)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  actionpack-xml_parser
+  bundler (>= 1.5.0)
+  capybara (~> 2.13)
+  csv (~> 3.0.1)
+  i18n (~> 0.7.0)
+  mail (~> 2.7.1)
+  mimemagic
+  mini_mime (~> 1.0.1)
+  mocha
+  mysql2 (~> 0.5.0)
+  net-ldap (~> 0.16.0)
+  nokogiri (~> 1.10.0)
+  pg (~> 1.1.4)
+  puma (~> 3.7)
+  rack-openid
+  rails (= 5.2.2)
+  rails-dom-testing
+  rbpdf (~> 1.19.6)
+  redcarpet (~> 3.4.0)
+  request_store (= 1.0.5)
+  rmagick (>= 2.14.0)
+  roadie-rails (~> 1.3.0)
+  rouge (~> 3.3.0)
+  ruby-openid (~> 2.3.0)
+  selenium-webdriver
+  simplecov (~> 0.14.1)
+  tzinfo-data
+  yard
+
+BUNDLED WITH
+   1.16.3
diff --git a/pkgs/applications/version-management/redmine/4.x/default.nix b/pkgs/applications/version-management/redmine/4.x/default.nix
new file mode 100644
index 00000000000..ba9f96f5a30
--- /dev/null
+++ b/pkgs/applications/version-management/redmine/4.x/default.nix
@@ -0,0 +1,43 @@
+{ stdenv, fetchurl, bundlerEnv, ruby }:
+
+let
+  version = "4.0.1";
+  rubyEnv = bundlerEnv {
+    name = "redmine-env-${version}";
+
+    inherit ruby;
+    gemdir = ./.;
+    groups = [ "ldap" "openid" ];
+  };
+in
+  stdenv.mkDerivation rec {
+    name = "redmine-${version}";
+
+    src = fetchurl {
+      url = "https://www.redmine.org/releases/${name}.tar.gz";
+      sha256 = "1zzn9rkh7x1h9f2shcc8qhb693hp0hpah0z53i6gfgg5p8k5hns1";
+    };
+
+    buildInputs = [ rubyEnv rubyEnv.wrappedRuby rubyEnv.bundler ];
+
+    buildPhase = ''
+      mv config config.dist
+      mv public/themes public/themes.dist
+    '';
+
+    installPhase = ''
+      mkdir -p $out/share
+      cp -r . $out/share/redmine
+      for i in config files log plugins public/plugin_assets public/themes tmp; do
+        rm -rf $out/share/redmine/$i
+        ln -fs /run/redmine/$i $out/share/redmine/$i
+      done
+    '';
+
+    meta = with stdenv.lib; {
+      homepage = http://www.redmine.org/;
+      platforms = platforms.linux;
+      maintainers = [ maintainers.garbas maintainers.aanderse ];
+      license = licenses.gpl2;
+    };
+  }
diff --git a/pkgs/applications/version-management/redmine/4.x/gemset.nix b/pkgs/applications/version-management/redmine/4.x/gemset.nix
new file mode 100644
index 00000000000..ce21a58b556
--- /dev/null
+++ b/pkgs/applications/version-management/redmine/4.x/gemset.nix
@@ -0,0 +1,622 @@
+{
+  actioncable = {
+    dependencies = ["actionpack" "nio4r" "websocket-driver"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0826k5ch0l03f9yrkxy69aiv039z4qi00lnahw2rzywd2iz6r68x";
+      type = "gem";
+    };
+    version = "5.2.2";
+  };
+  actionmailer = {
+    dependencies = ["actionpack" "actionview" "activejob" "mail" "rails-dom-testing"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0sfpb8s95cmkpp9ybyp2c88r55r5llscmmnkfwcwgasz9ncjiq5n";
+      type = "gem";
+    };
+    version = "5.2.2";
+  };
+  actionpack = {
+    dependencies = ["actionview" "activesupport" "rack" "rack-test" "rails-dom-testing" "rails-html-sanitizer"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0iwhbqqn0cm39dq040iwq8cfyclqk3kyzwlp5k3j5cz8k2668wws";
+      type = "gem";
+    };
+    version = "5.2.2";
+  };
+  actionpack-xml_parser = {
+    dependencies = ["actionpack" "railties"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1rnm6jrw3mzcf2g3q498igmhsn0kfkxq79w0nm532iclx4g4djs0";
+      type = "gem";
+    };
+    version = "2.0.1";
+  };
+  actionview = {
+    dependencies = ["activesupport" "builder" "erubi" "rails-dom-testing" "rails-html-sanitizer"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1lz04drbi1z0xhvb8jnr14pbf505lilr02arahxq7y3mxiz0rs8z";
+      type = "gem";
+    };
+    version = "5.2.2";
+  };
+  activejob = {
+    dependencies = ["activesupport" "globalid"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1jjkl62x2aprg55x9rpm0h2c82vr2qr989hg3l9r21l01q4822ir";
+      type = "gem";
+    };
+    version = "5.2.2";
+  };
+  activemodel = {
+    dependencies = ["activesupport"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1xmwi3mw8g4shbjvkhk72ra3r5jccbdsd4piphqka2y1h8s7sxvi";
+      type = "gem";
+    };
+    version = "5.2.2";
+  };
+  activerecord = {
+    dependencies = ["activemodel" "activesupport" "arel"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "19a0sns6a5wz2wym25lb1dv4lbrrl5sd1n15s5ky2636znmhz30y";
+      type = "gem";
+    };
+    version = "5.2.2";
+  };
+  activestorage = {
+    dependencies = ["actionpack" "activerecord" "marcel"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0c72837098sw384vk6dmrb2p7q3wx4swnibk6sw9dp4hn1vc4p31";
+      type = "gem";
+    };
+    version = "5.2.2";
+  };
+  activesupport = {
+    dependencies = ["concurrent-ruby" "i18n" "minitest" "tzinfo"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1iya7vxqwxysr74s7b4z1x19gmnx5advimzip3cbmsd5bd43wfgz";
+      type = "gem";
+    };
+    version = "5.2.2";
+  };
+  addressable = {
+    dependencies = ["public_suffix"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0bcm2hchn897xjhqj9zzsxf3n9xhddymj4lsclz508f4vw3av46l";
+      type = "gem";
+    };
+    version = "2.6.0";
+  };
+  arel = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1jk7wlmkr61f6g36w9s2sn46nmdg6wn2jfssrhbhirv5x9n95nk0";
+      type = "gem";
+    };
+    version = "9.0.0";
+  };
+  builder = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0qibi5s67lpdv1wgcj66wcymcr04q6j4mzws6a479n0mlrmh5wr1";
+      type = "gem";
+    };
+    version = "3.2.3";
+  };
+  capybara = {
+    dependencies = ["addressable" "mini_mime" "nokogiri" "rack" "rack-test" "xpath"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0yv77rnsjlvs8qpfn9n5vf1h6b9agxwhxw09gssbiw9zn9j20jh8";
+      type = "gem";
+    };
+    version = "2.18.0";
+  };
+  childprocess = {
+    dependencies = ["ffi"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0a61922kmvcxyj5l70fycapr87gz1dzzlkfpq85rfqk5vdh3d28p";
+      type = "gem";
+    };
+    version = "0.9.0";
+  };
+  concurrent-ruby = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1ixcx9pfissxrga53jbdpza85qd5f6b5nq1sfqa9rnfq82qnlbp1";
+      type = "gem";
+    };
+    version = "1.1.4";
+  };
+  crass = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0bpxzy6gjw9ggjynlxschbfsgmx8lv3zw1azkjvnb8b9i895dqfi";
+      type = "gem";
+    };
+    version = "1.0.4";
+  };
+  css_parser = {
+    dependencies = ["addressable"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0gwvf8mc8gnz4aizfijplv3594998h2j44ydakpzsdmkivs07v61";
+      type = "gem";
+    };
+    version = "1.6.0";
+  };
+  csv = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "19m22vlxddva301z2izvg06hldlc37nyzhin3kjjfcnlbb8imj33";
+      type = "gem";
+    };
+    version = "3.0.4";
+  };
+  docile = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0m8j31whq7bm5ljgmsrlfkiqvacrw6iz9wq10r3gwrv5785y8gjx";
+      type = "gem";
+    };
+    version = "1.1.5";
+  };
+  erubi = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1kagnf6ziahj0d781s6ryy6fwqwa3ad4xbzzj84p9m4nv4c2jir1";
+      type = "gem";
+    };
+    version = "1.8.0";
+  };
+  ffi = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0j8pzj8raxbir5w5k6s7a042sb5k02pg0f8s4na1r5lan901j00p";
+      type = "gem";
+    };
+    version = "1.10.0";
+  };
+  globalid = {
+    dependencies = ["activesupport"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1zkxndvck72bfw235bd9nl2ii0lvs5z88q14706cmn702ww2mxv1";
+      type = "gem";
+    };
+    version = "0.4.2";
+  };
+  htmlentities = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1nkklqsn8ir8wizzlakncfv42i32wc0w9hxp00hvdlgjr7376nhj";
+      type = "gem";
+    };
+    version = "4.3.4";
+  };
+  i18n = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1i5z1ykl8zhszsxcs8mzl8d0dxgs3ylz8qlzrw74jb0gplkx6758";
+      type = "gem";
+    };
+    version = "0.7.0";
+  };
+  json = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "01v6jjpvh3gnq6sgllpfqahlgxzj50ailwhj9b3cd20hi2dx0vxp";
+      type = "gem";
+    };
+    version = "2.1.0";
+  };
+  loofah = {
+    dependencies = ["crass" "nokogiri"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1ccsid33xjajd0im2xv941aywi58z7ihwkvaf1w2bv89vn5bhsjg";
+      type = "gem";
+    };
+    version = "2.2.3";
+  };
+  mail = {
+    dependencies = ["mini_mime"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "00wwz6ys0502dpk8xprwcqfwyf3hmnx6lgxaiq6vj43mkx43sapc";
+      type = "gem";
+    };
+    version = "2.7.1";
+  };
+  marcel = {
+    dependencies = ["mimemagic"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1nxbjmcyg8vlw6zwagf17l9y2mwkagmmkg95xybpn4bmf3rfnksx";
+      type = "gem";
+    };
+    version = "0.3.3";
+  };
+  metaclass = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0hp99y2b1nh0nr8pc398n3f8lakgci6pkrg4bf2b2211j1f6hsc5";
+      type = "gem";
+    };
+    version = "0.0.4";
+  };
+  method_source = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1pviwzvdqd90gn6y7illcdd9adapw8fczml933p5vl739dkvl3lq";
+      type = "gem";
+    };
+    version = "0.9.2";
+  };
+  mimemagic = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "04cp5sfbh1qx82yqxn0q75c7hlcx8y1dr5g3kyzwm4mx6wi2gifw";
+      type = "gem";
+    };
+    version = "0.3.3";
+  };
+  mini_mime = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1q4pshq387lzv9m39jv32vwb8wrq3wc4jwgl4jk209r4l33v09d3";
+      type = "gem";
+    };
+    version = "1.0.1";
+  };
+  mini_portile2 = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "15zplpfw3knqifj9bpf604rb3wc1vhq6363pd6lvhayng8wql5vy";
+      type = "gem";
+    };
+    version = "2.4.0";
+  };
+  minitest = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0icglrhghgwdlnzzp4jf76b0mbc71s80njn5afyfjn4wqji8mqbq";
+      type = "gem";
+    };
+    version = "5.11.3";
+  };
+  mocha = {
+    dependencies = ["metaclass"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "12aglpiq1h18j5a4rlwvnsvnsi2f3407v5xm59lgcg3ymlyak4al";
+      type = "gem";
+    };
+    version = "1.8.0";
+  };
+  mysql2 = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1a2kdjgzwh1p2rkcmxaawy6ibi32b04wbdd5d4wr8i342pq76di4";
+      type = "gem";
+    };
+    version = "0.5.2";
+  };
+  net-ldap = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "016igqz81a8zcwqzp5bbhryqmb2skmyf57ij3nb5z8sxwhw22jgh";
+      type = "gem";
+    };
+    version = "0.16.1";
+  };
+  nio4r = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1a41ca1kpdmrypjp9xbgvckpy8g26zxphkja9vk7j5wl4n8yvlyr";
+      type = "gem";
+    };
+    version = "2.3.1";
+  };
+  nokogiri = {
+    dependencies = ["mini_portile2"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "09zll7c6j7xr6wyvh5mm5ncj6pkryp70ybcsxdbw1nyphx5dh184";
+      type = "gem";
+    };
+    version = "1.10.1";
+  };
+  pg = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0fmnyxcyrvgdbgq7m09whgn9i8rwfybk0w8aii1nc4g5kqw0k2jy";
+      type = "gem";
+    };
+    version = "1.1.4";
+  };
+  public_suffix = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "08q64b5br692dd3v0a9wq9q5dvycc6kmiqmjbdxkxbfizggsvx6l";
+      type = "gem";
+    };
+    version = "3.0.3";
+  };
+  puma = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1k7dqxnq0dnf5rxkgs9rknclkn3ah7lsdrk6nrqxla8qzy31wliq";
+      type = "gem";
+    };
+    version = "3.12.0";
+  };
+  rack = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1pcgv8dv4vkaczzlix8q3j68capwhk420cddzijwqgi2qb4lm1zm";
+      type = "gem";
+    };
+    version = "2.0.6";
+  };
+  rack-openid = {
+    dependencies = ["rack" "ruby-openid"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0sg85yn981j3a0iri3ch4znzdwscvz29l7vrk3dafqw4fdg31llc";
+      type = "gem";
+    };
+    version = "1.4.2";
+  };
+  rack-test = {
+    dependencies = ["rack"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0rh8h376mx71ci5yklnpqqn118z3bl67nnv5k801qaqn1zs62h8m";
+      type = "gem";
+    };
+    version = "1.1.0";
+  };
+  rails = {
+    dependencies = ["actioncable" "actionmailer" "actionpack" "actionview" "activejob" "activemodel" "activerecord" "activestorage" "activesupport" "railties" "sprockets-rails"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1m9cszds68dsiycciiayd3c9g90s2yzn1izkr3gpgqkfw6dmvzyr";
+      type = "gem";
+    };
+    version = "5.2.2";
+  };
+  rails-dom-testing = {
+    dependencies = ["activesupport" "nokogiri"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1lfq2a7kp2x64dzzi5p4cjcbiv62vxh9lyqk2f0rqq3fkzrw8h5i";
+      type = "gem";
+    };
+    version = "2.0.3";
+  };
+  rails-html-sanitizer = {
+    dependencies = ["loofah"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1gv7vr5d9g2xmgpjfq4nxsqr70r9pr042r9ycqqnfvw5cz9c7jwr";
+      type = "gem";
+    };
+    version = "1.0.4";
+  };
+  railties = {
+    dependencies = ["actionpack" "activesupport" "method_source" "rake" "thor"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "00pnylmbz4c46mxw5lhxi8h39lndfg6fs1hpd0qd6swnjhkqsr1l";
+      type = "gem";
+    };
+    version = "5.2.2";
+  };
+  rake = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1sy5a7nh6xjdc9yhcw31jji7ssrf9v5806hn95gbrzr998a2ydjn";
+      type = "gem";
+    };
+    version = "12.3.2";
+  };
+  rbpdf = {
+    dependencies = ["htmlentities" "rbpdf-font"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0fnhcn4z2zz6ic1yvl5hmhwmkdnybh8f8fnk1ni7bvl2s4ig5195";
+      type = "gem";
+    };
+    version = "1.19.8";
+  };
+  rbpdf-font = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0pxlr0l4vf785qpy55m439dyii63a26l0sd0yyhbwwcy9zm9hd1v";
+      type = "gem";
+    };
+    version = "1.19.1";
+  };
+  redcarpet = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0h9qz2hik4s9knpmbwrzb3jcp3vc5vygp9ya8lcpl7f1l9khmcd7";
+      type = "gem";
+    };
+    version = "3.4.0";
+  };
+  request_store = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1ky19wb6mpq6dxb81a0h4hnzx7a4ka99n9ay2syi68djbr4bkbbh";
+      type = "gem";
+    };
+    version = "1.0.5";
+  };
+  rmagick = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0m9x15cdlkcb9826s3s2jd97hxf50hln22p94x8hcccxi1lwklq6";
+      type = "gem";
+    };
+    version = "2.16.0";
+  };
+  roadie = {
+    dependencies = ["css_parser" "nokogiri"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0l3s80394yijvz0fsvfkw0azsi9yxsdkxd8lpas0bd7wlndjvmxx";
+      type = "gem";
+    };
+    version = "3.4.0";
+  };
+  roadie-rails = {
+    dependencies = ["railties" "roadie"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "02km0ama85mkw7kkn6qif86b781pglfdmqrwx5s6hwjlzk16qih3";
+      type = "gem";
+    };
+    version = "1.3.0";
+  };
+  rouge = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1digsi2s8wyzx8vsqcxasw205lg6s7izx8jypl8rrpjwshmv83ql";
+      type = "gem";
+    };
+    version = "3.3.0";
+  };
+  ruby-openid = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0yzaf2c1i88757554wk38rxqmj0xzgmwk2zx7gi98w2zx42d17pn";
+      type = "gem";
+    };
+    version = "2.3.0";
+  };
+  rubyzip = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1n1lb2sdwh9h27y244hxzg1lrxxg2m53pk1vq7p33bna003qkyrj";
+      type = "gem";
+    };
+    version = "1.2.2";
+  };
+  selenium-webdriver = {
+    dependencies = ["childprocess" "rubyzip"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "114hv2ajmh6d186v2w887yqakqcxyxq367l0iakrrpvwviknrhfs";
+      type = "gem";
+    };
+    version = "3.141.0";
+  };
+  simplecov = {
+    dependencies = ["docile" "json" "simplecov-html"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1r9fnsnsqj432cmrpafryn8nif3x0qg9mdnvrcf0wr01prkdlnww";
+      type = "gem";
+    };
+    version = "0.14.1";
+  };
+  simplecov-html = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1lihraa4rgxk8wbfl77fy9sf0ypk31iivly8vl3w04srd7i0clzn";
+      type = "gem";
+    };
+    version = "0.10.2";
+  };
+  sprockets = {
+    dependencies = ["concurrent-ruby" "rack"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "182jw5a0fbqah5w9jancvfmjbk88h8bxdbwnl4d3q809rpxdg8ay";
+      type = "gem";
+    };
+    version = "3.7.2";
+  };
+  sprockets-rails = {
+    dependencies = ["actionpack" "activesupport" "sprockets"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0ab42pm8p5zxpv3sfraq45b9lj39cz9mrpdirm30vywzrwwkm5p1";
+      type = "gem";
+    };
+    version = "3.2.1";
+  };
+  thor = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1yhrnp9x8qcy5vc7g438amd5j9sw83ih7c30dr6g6slgw9zj3g29";
+      type = "gem";
+    };
+    version = "0.20.3";
+  };
+  thread_safe = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0nmhcgq6cgz44srylra07bmaw99f5271l0dpsvl5f75m44l0gmwy";
+      type = "gem";
+    };
+    version = "0.3.6";
+  };
+  tzinfo = {
+    dependencies = ["thread_safe"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1fjx9j327xpkkdlxwmkl3a8wqj7i4l4jwlrv3z13mg95z9wl253z";
+      type = "gem";
+    };
+    version = "1.2.5";
+  };
+  websocket-driver = {
+    dependencies = ["websocket-extensions"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "1551k3fs3kkb3ghqfj3n5lps0ikb9pyrdnzmvgfdxy8574n4g1dn";
+      type = "gem";
+    };
+    version = "0.7.0";
+  };
+  websocket-extensions = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "034sdr7fd34yag5l6y156rkbhiqgmy395m231dwhlpcswhs6d270";
+      type = "gem";
+    };
+    version = "0.1.3";
+  };
+  xpath = {
+    dependencies = ["nokogiri"];
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "0bh8lk9hvlpn7vmi6h4hkcwjzvs2y0cmkk3yjjdr8fxvj6fsgzbd";
+      type = "gem";
+    };
+    version = "3.2.0";
+  };
+  yard = {
+    source = {
+      remotes = ["https://rubygems.org"];
+      sha256 = "07fykkfyrwqkfnxx9i5w6adyiadz00h497c516n96rgvs7alc74f";
+      type = "gem";
+    };
+    version = "0.9.18";
+  };
+}
\ No newline at end of file
diff --git a/pkgs/applications/version-management/redmine/default.nix b/pkgs/applications/version-management/redmine/default.nix
index 6e5a2dbbdf7..02ae5da0f3f 100644
--- a/pkgs/applications/version-management/redmine/default.nix
+++ b/pkgs/applications/version-management/redmine/default.nix
@@ -37,7 +37,7 @@ in
     meta = with stdenv.lib; {
       homepage = http://www.redmine.org/;
       platforms = platforms.linux;
-      maintainers = [ maintainers.garbas ];
+      maintainers = [ maintainers.garbas maintainers.aanderse ];
       license = licenses.gpl2;
     };
   }
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 5578106651f..5c2ed177d32 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -5086,6 +5086,8 @@ in
   redir = callPackage ../tools/networking/redir { };
 
   redmine = callPackage ../applications/version-management/redmine { ruby = pkgs.ruby_2_4; };
+  # failed to build websocket-driver gem with ruby 2.6, so sticking to 2.5 for now
+  redmine_4 = callPackage ../applications/version-management/redmine/4.x { ruby = pkgs.ruby_2_5; };
 
   redsocks = callPackage ../tools/networking/redsocks { };