diff --git a/package.json b/package.json
index ce7e62573a3ce1c3e9db88625544a5a0cfc92c48..22100776d13cc0a6358bbebd4c7d40b982374238 100644
--- a/package.json
+++ b/package.json
@@ -9,6 +9,7 @@
   "private": true,
   "dependencies": {
     "body-parser": "^1.18.2",
+    "cors": "^2.8.4",
     "dotenv": "^4.0.0",
     "express": "^4.16.2",
     "firebase-admin": "^5.5.1",
@@ -24,7 +25,6 @@
   },
   "scripts": {
     "env:gen": "bash misc/scripts/env-gen",
-
     "prepare": "bash misc/scripts/env-gen",
     "start": "bash misc/scripts/start"
   }
diff --git a/yarn.lock b/yarn.lock
index 8081b03eeca1d46026751322ae792c10607cc50f..58c63d4e4808e30cc5082655e4ab465aaaf71da3 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -595,6 +595,13 @@ core-util-is@1.0.2, core-util-is@~1.0.0:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/core-util-is/-/core-util-is-1.0.2.tgz#b5fd54220aa2bc5ab57aab7140c940754503c1a7"
 
+cors@^2.8.4:
+  version "2.8.4"
+  resolved "https://registry.yarnpkg.com/cors/-/cors-2.8.4.tgz#2bd381f2eb201020105cd50ea59da63090694686"
+  dependencies:
+    object-assign "^4"
+    vary "^1"
+
 create-error-class@^3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/create-error-class/-/create-error-class-3.0.2.tgz#06be7abef947a3f14a30fd610671d401bca8b7b6"
@@ -1850,7 +1857,7 @@ oauth-sign@~0.8.1, oauth-sign@~0.8.2:
   version "0.8.2"
   resolved "https://registry.yarnpkg.com/oauth-sign/-/oauth-sign-0.8.2.tgz#46a6ab7f0aead8deae9ec0565780b7d4efeb9d43"
 
-object-assign@^4.0.1, object-assign@^4.1.0:
+object-assign@^4, object-assign@^4.0.1, object-assign@^4.1.0:
   version "4.1.1"
   resolved "https://registry.yarnpkg.com/object-assign/-/object-assign-4.1.1.tgz#2109adc7965887cfc05cbbd442cac8bfbb360863"
 
@@ -2613,7 +2620,7 @@ validate-npm-package-license@^3.0.1:
     spdx-correct "~1.0.0"
     spdx-expression-parse "~1.0.0"
 
-vary@~1.1.2:
+vary@^1, vary@~1.1.2:
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/vary/-/vary-1.1.2.tgz#2299f02c6ded30d4a5961b0b9f74524a18f634fc"