diff --git a/package.json b/package.json
index b112d81f..322683ae 100644
--- a/package.json
+++ b/package.json
@@ -30,7 +30,7 @@
   "typings": "index.d.ts",
   "homepage": "https://github.com/ocombe/ngx-translate",
   "peerDependencies": {
-    "@angular/core": ">=2.0.0"
+    "@angular/core": ">=4.0.0"
   },
   "devDependencies": {
     "@angular/animations": "4.1.3",
diff --git a/src/translate.service.ts b/src/translate.service.ts
index ed7deeda..f7156be7 100644
--- a/src/translate.service.ts
+++ b/src/translate.service.ts
@@ -1,4 +1,4 @@
-import {Injectable, EventEmitter, Inject, OpaqueToken} from "@angular/core";
+import {Injectable, EventEmitter, Inject, InjectionToken} from "@angular/core";
 import {Observable} from "rxjs/Observable";
 import {Observer} from "rxjs/Observer";
 import "rxjs/add/observable/of";
@@ -17,8 +17,8 @@ import {MissingTranslationHandler, MissingTranslationHandlerParams} from "./miss
 import {TranslateParser} from "./translate.parser";
 import {mergeDeep, isDefined} from "./util";
 
-export const USE_STORE = new OpaqueToken('USE_STORE');
-export const USE_DEFAULT_LANG = new OpaqueToken('USE_DEFAULT_LANG');
+export const USE_STORE = new InjectionToken<string>('USE_STORE');
+export const USE_DEFAULT_LANG = new InjectionToken<string>('USE_DEFAULT_LANG');
 
 export interface TranslationChangeEvent {
     translations: any;
diff --git a/yarn.lock b/yarn.lock
index 88abe6be..cd2e1760 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2339,7 +2339,7 @@ lodash.templatesettings@^3.0.0:
     lodash._reinterpolate "^3.0.0"
     lodash.escape "^3.0.0"
 
-lodash@4.17.2, lodash@^4.2.0, lodash@^4.3.0:
+lodash@4.17.2:
   version "4.17.2"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.2.tgz#34a3055babe04ce42467b607d700072c7ff6bf42"
 
@@ -2347,7 +2347,7 @@ lodash@^3.6.0, lodash@^3.8.0:
   version "3.10.1"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-3.10.1.tgz#5bf45e8e49ba4189e17d482789dfd15bd140b7b6"
 
-lodash@^4.0.0, lodash@^4.13.1, lodash@^4.14.0, lodash@^4.17.4, lodash@^4.5.0:
+lodash@^4.0.0, lodash@^4.13.1, lodash@^4.14.0, lodash@^4.17.4, lodash@^4.2.0, lodash@^4.3.0, lodash@^4.5.0:
   version "4.17.4"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.4.tgz#78203a4d1c328ae1d86dca6460e369b57f4055ae"
 
@@ -3003,11 +3003,10 @@ read-pkg@^1.0.0:
     normalize-package-data "^2.3.2"
     path-type "^1.0.0"
 
-"readable-stream@^2.0.0 || ^1.1.13", readable-stream@^2.0.2, readable-stream@^2.0.5, readable-stream@^2.1.0, readable-stream@^2.2.2:
-  version "2.2.2"
-  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-2.2.2.tgz#a9e6fec3c7dda85f8bb1b3ba7028604556fc825e"
+"readable-stream@^2.0.0 || ^1.1.13", readable-stream@^2.0.1, readable-stream@^2.0.2, readable-stream@^2.0.5, readable-stream@~2.0.0, readable-stream@~2.0.5:
+  version "2.0.6"
+  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-2.0.6.tgz#8f90341e68a53ccc928788dacfcd11b36eb9b78e"
   dependencies:
-    buffer-shims "^1.0.0"
     core-util-is "~1.0.0"
     inherits "~2.0.1"
     isarray "~1.0.0"
@@ -3015,10 +3014,11 @@ read-pkg@^1.0.0:
     string_decoder "~0.10.x"
     util-deprecate "~1.0.1"
 
-readable-stream@^2.0.1, readable-stream@~2.0.0, readable-stream@~2.0.5:
-  version "2.0.6"
-  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-2.0.6.tgz#8f90341e68a53ccc928788dacfcd11b36eb9b78e"
+readable-stream@^2.1.0, readable-stream@^2.2.2:
+  version "2.2.2"
+  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-2.2.2.tgz#a9e6fec3c7dda85f8bb1b3ba7028604556fc825e"
   dependencies:
+    buffer-shims "^1.0.0"
     core-util-is "~1.0.0"
     inherits "~2.0.1"
     isarray "~1.0.0"
@@ -3235,11 +3235,11 @@ resolve-dir@^0.1.0:
     expand-tilde "^1.2.2"
     global-modules "^0.2.3"
 
-resolve@1.1.x, resolve@^1.1.6:
+resolve@1.1.x:
   version "1.1.7"
   resolved "https://registry.yarnpkg.com/resolve/-/resolve-1.1.7.tgz#203114d82ad2c5ed9e8e0411b3932875e889e97b"
 
-resolve@^1.3.2:
+resolve@^1.1.6, resolve@^1.3.2:
   version "1.3.3"
   resolved "https://registry.yarnpkg.com/resolve/-/resolve-1.3.3.tgz#655907c3469a8680dc2de3a275a8fdd69691f0e5"
   dependencies:
@@ -3807,16 +3807,7 @@ typescript@2.3.3:
   version "2.3.3"
   resolved "https://registry.yarnpkg.com/typescript/-/typescript-2.3.3.tgz#9639f3c3b40148e8ca97fe08a51dd1891bb6be22"
 
-uglify-js@^2.6:
-  version "2.8.15"
-  resolved "https://registry.yarnpkg.com/uglify-js/-/uglify-js-2.8.15.tgz#835dd4cd5872554756e6874508d0d0561704d94d"
-  dependencies:
-    source-map "~0.5.1"
-    yargs "~3.10.0"
-  optionalDependencies:
-    uglify-to-browserify "~1.0.0"
-
-uglify-js@^2.8.27:
+uglify-js@^2.6, uglify-js@^2.8.27:
   version "2.8.27"
   resolved "https://registry.yarnpkg.com/uglify-js/-/uglify-js-2.8.27.tgz#47787f912b0f242e5b984343be8e35e95f694c9c"
   dependencies: