diff --git a/packages/strapi-plugin-users-permissions/controllers/Auth.js b/packages/strapi-plugin-users-permissions/controllers/Auth.js
index 87ffc55ac6..a11db3d3c3 100644
--- a/packages/strapi-plugin-users-permissions/controllers/Auth.js
+++ b/packages/strapi-plugin-users-permissions/controllers/Auth.js
@@ -71,12 +71,17 @@ module.exports = {
       }
     } else {
       // Connect the user thanks to the third-party provider.
+      let user, error;
       try {
-        const [user, error] = await strapi.plugins['users-permissions'].services.providers.connect(provider, ctx.query);
+        [user, error] = await strapi.plugins['users-permissions'].services.providers.connect(provider, ctx.query);
       } catch([user, error]) {
         return ctx.badRequest(null, (error === 'array') ? (ctx.request.admin ? error[0] : error[1]) : error);
       }
 
+      if (!user) {
+        return ctx.badRequest(null, (error === 'array') ? (ctx.request.admin ? error[0] : error[1]) : error);
+      }
+
       ctx.send({
         jwt: strapi.plugins['users-permissions'].services.jwt.issue(user),
         user: _.omit(user.toJSON ? user.toJSON() : user, ['password', 'resetPasswordToken'])
diff --git a/packages/strapi-plugin-users-permissions/services/Providers.js b/packages/strapi-plugin-users-permissions/services/Providers.js
index 7d1ce67f55..004c242a9c 100644
--- a/packages/strapi-plugin-users-permissions/services/Providers.js
+++ b/packages/strapi-plugin-users-permissions/services/Providers.js
@@ -11,27 +11,6 @@ const request = require('request');
 // Purest strategies.
 const Purest = require('purest');
 
-const facebook = new Purest({
-  provider: 'facebook'
-});
-
-const github = new Purest({
-  provider: 'github',
-  defaults: {
-    headers: {
-      'user-agent': 'strapi'
-    }
-  }
-});
-
-const google = new Purest({
-  provider: 'google'
-});
-
-const twitter = new Purest({
-  provider: 'twitter'
-});
-
 /**
  * Connect thanks to a third-party provider.
  *
@@ -73,7 +52,7 @@ exports.connect = (provider, query) => {
         }
 
         if (user && user.provider === provider) {
-          return resolve([null, [{ messages: [{ id: 'Auth.form.error.email.taken' }] }], 'Email is already taken.']);
+          return resolve([user, null]);
         }
 
         if (user && user.provider !== provider && strapi.plugins['users-permissions'].config.advanced.unique_email) {
@@ -111,6 +90,10 @@ const getProfile = (provider, query, callback) => {
 
   switch (provider) {
     case 'facebook':
+      const facebook = new Purest({
+        provider: 'facebook'
+      });
+
       facebook.query().get('me?fields=name,email').auth(access_token).request((err, res, body) => {
         if (err) {
           callback(err);
@@ -123,18 +106,31 @@ const getProfile = (provider, query, callback) => {
       });
       break;
     case 'google':
+      const google = new Purest({
+        provider: 'google'
+      });
+
       google.query('plus').get('people/me').auth(access_token).request((err, res, body) => {
         if (err) {
           callback(err);
         } else {
           callback(null, {
-            username: body.displayName,
+            username: body.displayName || body.emails[0].value,
             email: body.emails[0].value
           });
         }
       });
       break;
     case 'github':
+      const github = new Purest({
+        provider: 'github',
+        defaults: {
+          headers: {
+            'user-agent': 'strapi'
+          }
+        }
+      });
+
       request.post({
         url: 'https://github.com/login/oauth/access_token',
         form: {
@@ -156,7 +152,13 @@ const getProfile = (provider, query, callback) => {
       });
       break;
     case 'twitter':
-      twitter.query().get('account/verify_credentials').auth(access_token, query.access_secret).qs({screen_name: query['raw[screen_name]']}).qs({include_email: 'true'}).request((err, res, body) => {
+      const twitter = new Purest({
+        provider: 'twitter',
+        key: strapi.plugins['users-permissions'].config.grant.twitter.key,
+        secret: strapi.plugins['users-permissions'].config.grant.twitter.secret
+      });
+
+      twitter.query().get('account/verify_credentials').auth(access_token, query.access_secret).qs({screen_name: query['raw[screen_name]'], include_email: 'true'}).request((err, res, body) => {
         if (err) {
           callback(err);
         } else {