diff --git a/backend/session.coffee b/backend/session.coffee
index 2c4b8a4..afcc7ab 100644
--- a/backend/session.coffee
+++ b/backend/session.coffee
@@ -11,41 +11,36 @@ EXPIRY =
   login:   1 * 60 * 60 * 24 * 7 * 4
 
 
-FFTCGSESSION = () ->
-  @db = redis.createClient
-    host: 'redis'
-    port: 6379
+class FFTCGSESSION
+  constructor: ->
+    @db = redis.createClient
+      host: 'redis'
+      port: 6379
 
-  @db.on 'error', (err) ->
-    logger.error err.message
+    @db.on 'error', (err) ->
+      logger.error err.message
 
-  return
+  start: (data) ->
+    new Promise (resolve) =>
+      # hash data
+      hmac = crypto.createHmac 'sha256', Math.random().toString()
+      hmac.update (JSON.stringify data)
+      digest = hmac.digest 'base64'
+      logger.debug 'digest', digest
 
-FFTCGSESSION::start = (data) ->
-  that = @
+      # push (hash, data) into DB for the configured timespan
+      @db.setex digest, EXPIRY.login, (JSON.stringify data), (err) ->
+        resolve digest
 
-  new Promise (resolve) ->
-    # hash data
-    hmac = crypto.createHmac 'sha256', Math.random().toString()
-    hmac.update (JSON.stringify data)
-    digest = hmac.digest 'base64'
-    logger.debug 'digest', digest
+  check: (digest) ->
+    new Promise (resolve, reject) =>
+      # refresh expiry timer on digest
+      @db.expire digest, EXPIRY.login, (err, res) =>
+        if res == 0
+          reject null
 
-    # push (hash, data) into DB for the configured timespan
-    that.db.setex digest, EXPIRY.login, (JSON.stringify data), (err) ->
-      resolve digest
-
-FFTCGSESSION::check = (digest) ->
-  that = @
-
-  new Promise (resolve, reject) ->
-    # refresh expiry timer on digest
-    that.db.expire digest, EXPIRY.login, (err, res) ->
-      if res == 0
-        reject null
-
-      else
-        that.db.get digest, (err, res) ->
-          resolve JSON.parse res
+        else
+          @db.get digest, (err, res) ->
+            resolve JSON.parse res
 
 module.exports = FFTCGSESSION