diff --git a/Cakefile b/Cakefile
index f972f3b..3b5d7a4 100644
--- a/Cakefile
+++ b/Cakefile
@@ -18,7 +18,7 @@ for source in sources
   sourcestring += 'src/'+source+' '
 
 task 'watch', 'Watch source files and build changes', ->
-  watch = spawn "coffee", ['-c', '-w', '-m', '--no-header', '-j', 'lib/index.js', sourcestring]
+  watch = spawn "node_modules/coffeescript/bin/coffee", ['-c', '-w', '-m', '--no-header', '-j', 'lib/index.js', sourcestring]
   watch.stdout.on 'data', (data) -> console.log data.toString().trim()
 
 task 'compile', 'Compile all CoffeeScript files', ->
@@ -28,7 +28,7 @@ task 'compile', 'Compile all CoffeeScript files', ->
 
   # run coffee-script compile
   exec "cat #{sourcestring} > lib/index.coffee"
-  exec "coffee --compile --map --no-header lib/index.coffee", (err, stdout, stderr) ->
+  exec "node_modules/coffeescript/bin/coffee --compile --map --no-header lib/index.coffee", (err, stdout, stderr) ->
     if err
       util.log err
       process.exit 1 # abort npm packaging
diff --git a/package.json b/package.json
index f028f6c..fccc332 100644
--- a/package.json
+++ b/package.json
@@ -2,12 +2,19 @@
   "name": "salet",
   "version": "1.8.5",
   "description": "A general client-side framework for cybertext interactive fiction games.",
-  "keywords": ["ifiction", "interactive fiction", "games", "coffee-script", "text", "menu"],
+  "keywords": [
+    "ifiction",
+    "interactive fiction",
+    "games",
+    "coffee-script",
+    "text",
+    "menu"
+  ],
   "homepage": "https://salet.su",
   "bugs": {
-    "url" : "https://gitlab.com/oreolek/salet-module/issues"
+    "url": "https://gitlab.com/oreolek/salet-module/issues"
   },
-  "license" : "MIT",
+  "license": "MIT",
   "dependencies": {},
   "private": false,
   "author": {
@@ -16,7 +23,7 @@
     "url": "https://oreolek.ru"
   },
   "devDependencies": {
-    "coffee-script": "*"
+    "coffeescript": "^2.0.0"
   },
   "main": "lib/index.min.js",
   "types": "./typings/salet/index.d.ts",
diff --git a/yarn.lock b/yarn.lock
new file mode 100644
index 0000000..3d9429b
--- /dev/null
+++ b/yarn.lock
@@ -0,0 +1,317 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+ansi-regex@^2.0.0:
+  version "2.1.1"
+  resolved "https://registry.yarnpkg.com/ansi-regex/-/ansi-regex-2.1.1.tgz#c3b33ab5ee360d86e0e628f0468ae7ef27d654df"
+
+ansi-styles@^2.2.1:
+  version "2.2.1"
+  resolved "https://registry.yarnpkg.com/ansi-styles/-/ansi-styles-2.2.1.tgz#b432dd3358b634cf75e1e4664368240533c1ddbe"
+
+babel-code-frame@^6.26.0:
+  version "6.26.0"
+  resolved "https://registry.yarnpkg.com/babel-code-frame/-/babel-code-frame-6.26.0.tgz#63fd43f7dc1e3bb7ce35947db8fe369a3f58c74b"
+  dependencies:
+    chalk "^1.1.3"
+    esutils "^2.0.2"
+    js-tokens "^3.0.2"
+
+babel-core@^6, babel-core@^6.26.0:
+  version "6.26.0"
+  resolved "https://registry.yarnpkg.com/babel-core/-/babel-core-6.26.0.tgz#af32f78b31a6fcef119c87b0fd8d9753f03a0bb8"
+  dependencies:
+    babel-code-frame "^6.26.0"
+    babel-generator "^6.26.0"
+    babel-helpers "^6.24.1"
+    babel-messages "^6.23.0"
+    babel-register "^6.26.0"
+    babel-runtime "^6.26.0"
+    babel-template "^6.26.0"
+    babel-traverse "^6.26.0"
+    babel-types "^6.26.0"
+    babylon "^6.18.0"
+    convert-source-map "^1.5.0"
+    debug "^2.6.8"
+    json5 "^0.5.1"
+    lodash "^4.17.4"
+    minimatch "^3.0.4"
+    path-is-absolute "^1.0.1"
+    private "^0.1.7"
+    slash "^1.0.0"
+    source-map "^0.5.6"
+
+babel-generator@^6.26.0:
+  version "6.26.0"
+  resolved "https://registry.yarnpkg.com/babel-generator/-/babel-generator-6.26.0.tgz#ac1ae20070b79f6e3ca1d3269613053774f20dc5"
+  dependencies:
+    babel-messages "^6.23.0"
+    babel-runtime "^6.26.0"
+    babel-types "^6.26.0"
+    detect-indent "^4.0.0"
+    jsesc "^1.3.0"
+    lodash "^4.17.4"
+    source-map "^0.5.6"
+    trim-right "^1.0.1"
+
+babel-helpers@^6.24.1:
+  version "6.24.1"
+  resolved "https://registry.yarnpkg.com/babel-helpers/-/babel-helpers-6.24.1.tgz#3471de9caec388e5c850e597e58a26ddf37602b2"
+  dependencies:
+    babel-runtime "^6.22.0"
+    babel-template "^6.24.1"
+
+babel-messages@^6.23.0:
+  version "6.23.0"
+  resolved "https://registry.yarnpkg.com/babel-messages/-/babel-messages-6.23.0.tgz#f3cdf4703858035b2a2951c6ec5edf6c62f2630e"
+  dependencies:
+    babel-runtime "^6.22.0"
+
+babel-register@^6.26.0:
+  version "6.26.0"
+  resolved "https://registry.yarnpkg.com/babel-register/-/babel-register-6.26.0.tgz#6ed021173e2fcb486d7acb45c6009a856f647071"
+  dependencies:
+    babel-core "^6.26.0"
+    babel-runtime "^6.26.0"
+    core-js "^2.5.0"
+    home-or-tmp "^2.0.0"
+    lodash "^4.17.4"
+    mkdirp "^0.5.1"
+    source-map-support "^0.4.15"
+
+babel-runtime@^6.22.0, babel-runtime@^6.26.0:
+  version "6.26.0"
+  resolved "https://registry.yarnpkg.com/babel-runtime/-/babel-runtime-6.26.0.tgz#965c7058668e82b55d7bfe04ff2337bc8b5647fe"
+  dependencies:
+    core-js "^2.4.0"
+    regenerator-runtime "^0.11.0"
+
+babel-template@^6.24.1, babel-template@^6.26.0:
+  version "6.26.0"
+  resolved "https://registry.yarnpkg.com/babel-template/-/babel-template-6.26.0.tgz#de03e2d16396b069f46dd9fff8521fb1a0e35e02"
+  dependencies:
+    babel-runtime "^6.26.0"
+    babel-traverse "^6.26.0"
+    babel-types "^6.26.0"
+    babylon "^6.18.0"
+    lodash "^4.17.4"
+
+babel-traverse@^6.26.0:
+  version "6.26.0"
+  resolved "https://registry.yarnpkg.com/babel-traverse/-/babel-traverse-6.26.0.tgz#46a9cbd7edcc62c8e5c064e2d2d8d0f4035766ee"
+  dependencies:
+    babel-code-frame "^6.26.0"
+    babel-messages "^6.23.0"
+    babel-runtime "^6.26.0"
+    babel-types "^6.26.0"
+    babylon "^6.18.0"
+    debug "^2.6.8"
+    globals "^9.18.0"
+    invariant "^2.2.2"
+    lodash "^4.17.4"
+
+babel-types@^6.26.0:
+  version "6.26.0"
+  resolved "https://registry.yarnpkg.com/babel-types/-/babel-types-6.26.0.tgz#a3b073f94ab49eb6fa55cd65227a334380632497"
+  dependencies:
+    babel-runtime "^6.26.0"
+    esutils "^2.0.2"
+    lodash "^4.17.4"
+    to-fast-properties "^1.0.3"
+
+babylon@^6.18.0:
+  version "6.18.0"
+  resolved "https://registry.yarnpkg.com/babylon/-/babylon-6.18.0.tgz#af2f3b88fa6f5c1e4c634d1a0f8eac4f55b395e3"
+
+balanced-match@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/balanced-match/-/balanced-match-1.0.0.tgz#89b4d199ab2bee49de164ea02b89ce462d71b767"
+
+brace-expansion@^1.1.7:
+  version "1.1.8"
+  resolved "https://registry.yarnpkg.com/brace-expansion/-/brace-expansion-1.1.8.tgz#c07b211c7c952ec1f8efd51a77ef0d1d3990a292"
+  dependencies:
+    balanced-match "^1.0.0"
+    concat-map "0.0.1"
+
+chalk@^1.1.3:
+  version "1.1.3"
+  resolved "https://registry.yarnpkg.com/chalk/-/chalk-1.1.3.tgz#a8115c55e4a702fe4d150abd3872822a7e09fc98"
+  dependencies:
+    ansi-styles "^2.2.1"
+    escape-string-regexp "^1.0.2"
+    has-ansi "^2.0.0"
+    strip-ansi "^3.0.0"
+    supports-color "^2.0.0"
+
+coffeescript@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/coffeescript/-/coffeescript-2.0.0.tgz#61bcc70989cc18a0aab6b3d8be110d2ec7743c9a"
+  optionalDependencies:
+    babel-core "^6"
+
+concat-map@0.0.1:
+  version "0.0.1"
+  resolved "https://registry.yarnpkg.com/concat-map/-/concat-map-0.0.1.tgz#d8a96bd77fd68df7793a73036a3ba0d5405d477b"
+
+convert-source-map@^1.5.0:
+  version "1.5.0"
+  resolved "https://registry.yarnpkg.com/convert-source-map/-/convert-source-map-1.5.0.tgz#9acd70851c6d5dfdd93d9282e5edf94a03ff46b5"
+
+core-js@^2.4.0, core-js@^2.5.0:
+  version "2.5.1"
+  resolved "https://registry.yarnpkg.com/core-js/-/core-js-2.5.1.tgz#ae6874dc66937789b80754ff5428df66819ca50b"
+
+debug@^2.6.8:
+  version "2.6.8"
+  resolved "https://registry.yarnpkg.com/debug/-/debug-2.6.8.tgz#e731531ca2ede27d188222427da17821d68ff4fc"
+  dependencies:
+    ms "2.0.0"
+
+detect-indent@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/detect-indent/-/detect-indent-4.0.0.tgz#f76d064352cdf43a1cb6ce619c4ee3a9475de208"
+  dependencies:
+    repeating "^2.0.0"
+
+escape-string-regexp@^1.0.2:
+  version "1.0.5"
+  resolved "https://registry.yarnpkg.com/escape-string-regexp/-/escape-string-regexp-1.0.5.tgz#1b61c0562190a8dff6ae3bb2cf0200ca130b86d4"
+
+esutils@^2.0.2:
+  version "2.0.2"
+  resolved "https://registry.yarnpkg.com/esutils/-/esutils-2.0.2.tgz#0abf4f1caa5bcb1f7a9d8acc6dea4faaa04bac9b"
+
+globals@^9.18.0:
+  version "9.18.0"
+  resolved "https://registry.yarnpkg.com/globals/-/globals-9.18.0.tgz#aa3896b3e69b487f17e31ed2143d69a8e30c2d8a"
+
+has-ansi@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/has-ansi/-/has-ansi-2.0.0.tgz#34f5049ce1ecdf2b0649af3ef24e45ed35416d91"
+  dependencies:
+    ansi-regex "^2.0.0"
+
+home-or-tmp@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/home-or-tmp/-/home-or-tmp-2.0.0.tgz#e36c3f2d2cae7d746a857e38d18d5f32a7882db8"
+  dependencies:
+    os-homedir "^1.0.0"
+    os-tmpdir "^1.0.1"
+
+invariant@^2.2.2:
+  version "2.2.2"
+  resolved "https://registry.yarnpkg.com/invariant/-/invariant-2.2.2.tgz#9e1f56ac0acdb6bf303306f338be3b204ae60360"
+  dependencies:
+    loose-envify "^1.0.0"
+
+is-finite@^1.0.0:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/is-finite/-/is-finite-1.0.2.tgz#cc6677695602be550ef11e8b4aa6305342b6d0aa"
+  dependencies:
+    number-is-nan "^1.0.0"
+
+js-tokens@^3.0.0, js-tokens@^3.0.2:
+  version "3.0.2"
+  resolved "https://registry.yarnpkg.com/js-tokens/-/js-tokens-3.0.2.tgz#9866df395102130e38f7f996bceb65443209c25b"
+
+jsesc@^1.3.0:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/jsesc/-/jsesc-1.3.0.tgz#46c3fec8c1892b12b0833db9bc7622176dbab34b"
+
+json5@^0.5.1:
+  version "0.5.1"
+  resolved "https://registry.yarnpkg.com/json5/-/json5-0.5.1.tgz#1eade7acc012034ad84e2396767ead9fa5495821"
+
+lodash@^4.17.4:
+  version "4.17.4"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.4.tgz#78203a4d1c328ae1d86dca6460e369b57f4055ae"
+
+loose-envify@^1.0.0:
+  version "1.3.1"
+  resolved "https://registry.yarnpkg.com/loose-envify/-/loose-envify-1.3.1.tgz#d1a8ad33fa9ce0e713d65fdd0ac8b748d478c848"
+  dependencies:
+    js-tokens "^3.0.0"
+
+minimatch@^3.0.4:
+  version "3.0.4"
+  resolved "https://registry.yarnpkg.com/minimatch/-/minimatch-3.0.4.tgz#5166e286457f03306064be5497e8dbb0c3d32083"
+  dependencies:
+    brace-expansion "^1.1.7"
+
+minimist@0.0.8:
+  version "0.0.8"
+  resolved "https://registry.yarnpkg.com/minimist/-/minimist-0.0.8.tgz#857fcabfc3397d2625b8228262e86aa7a011b05d"
+
+mkdirp@^0.5.1:
+  version "0.5.1"
+  resolved "https://registry.yarnpkg.com/mkdirp/-/mkdirp-0.5.1.tgz#30057438eac6cf7f8c4767f38648d6697d75c903"
+  dependencies:
+    minimist "0.0.8"
+
+ms@2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/ms/-/ms-2.0.0.tgz#5608aeadfc00be6c2901df5f9861788de0d597c8"
+
+number-is-nan@^1.0.0:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/number-is-nan/-/number-is-nan-1.0.1.tgz#097b602b53422a522c1afb8790318336941a011d"
+
+os-homedir@^1.0.0:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/os-homedir/-/os-homedir-1.0.2.tgz#ffbc4988336e0e833de0c168c7ef152121aa7fb3"
+
+os-tmpdir@^1.0.1:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/os-tmpdir/-/os-tmpdir-1.0.2.tgz#bbe67406c79aa85c5cfec766fe5734555dfa1274"
+
+path-is-absolute@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/path-is-absolute/-/path-is-absolute-1.0.1.tgz#174b9268735534ffbc7ace6bf53a5a9e1b5c5f5f"
+
+private@^0.1.7:
+  version "0.1.7"
+  resolved "https://registry.yarnpkg.com/private/-/private-0.1.7.tgz#68ce5e8a1ef0a23bb570cc28537b5332aba63ef1"
+
+regenerator-runtime@^0.11.0:
+  version "0.11.0"
+  resolved "https://registry.yarnpkg.com/regenerator-runtime/-/regenerator-runtime-0.11.0.tgz#7e54fe5b5ccd5d6624ea6255c3473be090b802e1"
+
+repeating@^2.0.0:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/repeating/-/repeating-2.0.1.tgz#5214c53a926d3552707527fbab415dbc08d06dda"
+  dependencies:
+    is-finite "^1.0.0"
+
+slash@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/slash/-/slash-1.0.0.tgz#c41f2f6c39fc16d1cd17ad4b5d896114ae470d55"
+
+source-map-support@^0.4.15:
+  version "0.4.18"
+  resolved "https://registry.yarnpkg.com/source-map-support/-/source-map-support-0.4.18.tgz#0286a6de8be42641338594e97ccea75f0a2c585f"
+  dependencies:
+    source-map "^0.5.6"
+
+source-map@^0.5.6:
+  version "0.5.7"
+  resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.5.7.tgz#8a039d2d1021d22d1ea14c80d8ea468ba2ef3fcc"
+
+strip-ansi@^3.0.0:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/strip-ansi/-/strip-ansi-3.0.1.tgz#6a385fb8853d952d5ff05d0e8aaf94278dc63dcf"
+  dependencies:
+    ansi-regex "^2.0.0"
+
+supports-color@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-2.0.0.tgz#535d045ce6b6363fa40117084629995e9df324c7"
+
+to-fast-properties@^1.0.3:
+  version "1.0.3"
+  resolved "https://registry.yarnpkg.com/to-fast-properties/-/to-fast-properties-1.0.3.tgz#b83571fa4d8c25b82e231b06e3a3055de4ca1a47"
+
+trim-right@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/trim-right/-/trim-right-1.0.1.tgz#cb2e1203067e0c8de1f614094b9fe45704ea6003"