diff --git a/.eslintrc b/.eslintrc
index 09b633ccd8..a11da84ae9 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -68,12 +68,12 @@
         "no-this-before-super": 2,
         "no-var": 2,
         "object-shorthand": 2,
-        "prefer-const": 2,
+        "prefer-const": 0,
         "prefer-spread": 2,
         "prefer-template": 2,
         "array-bracket-spacing": [2, "never"],
         "brace-style": [2, "1tbs", { "allowSingleLine": false }],
-        "camel-case": 2,
+        "camelcase": 2,
         "comma-spacing": 2,
         "comma-style": [2, "last"],
         "computed-property-spacing": [2, "never"],
@@ -98,7 +98,7 @@
         "operator-linebreak": [2, "after"],
         "quote-props": [2, "as-needed", { "keywords": true }],
         "semi-spacing": [2, {"before": false, "after": true}],
-        "space-after-keyword": 2,
+        "space-after-keywords": 2,
         "space-before-blocks": 2,
         "space-before-function-paren": 2,
         "space-before-keywords": 2,
@@ -109,7 +109,7 @@
         "spaced-comment": [2, "always", { exceptions: ["-"]}],
         "padded-blocks": [2, "never"],
         "no-multiple-empty-lines": [2, {max: 2}],
-        "lines-around-comment": [2, { "beforeBlockComment": true, "beforeLineComment": true }]
+        "lines-around-comment": [2, { "beforeBlockComment": true, "beforeLineComment": true, "allowBlockStart": true }]
     },
     "env": {
         "es6": true,
diff --git a/package.json b/package.json
index 4bdb699e78..480959e118 100644
--- a/package.json
+++ b/package.json
@@ -21,6 +21,7 @@
     "cookie-session": "^1.2.0",
     "coupon-code": "~0.3.0",
     "domain-middleware": "~0.1.0",
+    "estraverse": "^4.1.1",
     "express": "~4.13.3",
     "express-csv": "~0.6.0",
     "firebase": "^2.2.9",
diff --git a/tasks/gulp-eslint.js b/tasks/gulp-eslint.js
index cbb6c97928..7a30f35ca1 100644
--- a/tasks/gulp-eslint.js
+++ b/tasks/gulp-eslint.js
@@ -2,7 +2,10 @@ import gulp from 'gulp';
 import eslint from 'gulp-eslint';
 
 // TODO lint client
-// TDOO separate linting cong between 
+// TDOO separate linting cong between
+// TODO lint gulp tasks, tests, ...?
+// TODO what about prefer-const rule?
+// TODO remove estraverse dependency once https://github.com/adametry/gulp-eslint/issues/117 sorted out
 gulp.task('lint:server', () => {
   // Ignore .coffee files
   return gulp
diff --git a/website/src/libs/api-v3/errors.js b/website/src/libs/api-v3/errors.js
index c4afdd956c..c1ebec5d57 100644
--- a/website/src/libs/api-v3/errors.js
+++ b/website/src/libs/api-v3/errors.js
@@ -3,7 +3,7 @@
 // Base class for custom application errors
 // It extends Error and capture the stack trace
 class CustomError extends Error {
-  constructor() {
+  constructor () {
     super();
     Error.captureStackTrace(this, this.constructor);
   }
@@ -12,7 +12,7 @@ class CustomError extends Error {
 // NotAuthorized error with a 401 http error code
 // used when a request is not authorized
 class NotAuthorized extends CustomError {
-  constructor(customMessage) {
+  constructor (customMessage) {
     super();
     this.name = this.constructor.name;
     this.httpCode = 401;
@@ -24,7 +24,7 @@ class NotAuthorized extends CustomError {
 // used for requests not formatted correctly
 // TODO use for validation errors too?
 class BadRequest extends CustomError {
-  constructor(customMessage) {
+  constructor (customMessage) {
     super();
     this.name = this.constructor.name;
     this.httpCode = 400;
@@ -35,7 +35,7 @@ class BadRequest extends CustomError {
 // InternalError error with a 500 http error code
 // used when an unexpected, internal server error is thrown
 class InternalServerError extends CustomError {
-  constructor(customMessage) {
+  constructor (customMessage) {
     super();
     this.name = this.constructor.name;
     this.httpCode = 500;
diff --git a/website/src/libs/api-v3/logger.js b/website/src/libs/api-v3/logger.js
index 34f0bf002b..8a256a3461 100644
--- a/website/src/libs/api-v3/logger.js
+++ b/website/src/libs/api-v3/logger.js
@@ -5,7 +5,7 @@
 let winston = require('winston');
 let nconf = require('nconf');
 
-// TODO use const? 
+// TODO use const?
 // TODO move isProd to a single location
 let isProd = nconf.get('NODE_ENV') === 'production';
 
diff --git a/website/src/middlewares/api-v3/errorHandler.js b/website/src/middlewares/api-v3/errorHandler.js
index bdbaef9043..833c03b508 100644
--- a/website/src/middlewares/api-v3/errorHandler.js
+++ b/website/src/middlewares/api-v3/errorHandler.js
@@ -1,21 +1,22 @@
 'use strict';
 
-// The error handler middleware that handles all errors 
+// The error handler middleware that handles all errors
 // and respond to the client
 let logger = require('../../libs/api-v3/logger');
 let errors = require('../../libs/api-v3/errors');
 let CustomError = errors.CustomError;
 let InternalServerError = errors.InternalServerError;
 
-module.exports = function (err, req, res, next) {
+module.exports = function errorHandlerMiddleware (err, req, res, next) {
   // Log the original error with some metadata
   let stack = err.stack || err.message || err;
+
   logger.error(stack, {
     originalUrl: req.originalUrl,
     headers: req.headers,
     body: req.body
   });
-  
+
   // In case of a CustomError class, use it's data
   // Otherwise try to identify the type of error (mongoose validation, mongodb unique, ...)
   // If we can't identify it, respond with a generic 500 error
diff --git a/website/src/middlewares/api-v3/index.js b/website/src/middlewares/api-v3/index.js
index 0ab9de4fe4..61ac54c4dc 100644
--- a/website/src/middlewares/api-v3/index.js
+++ b/website/src/middlewares/api-v3/index.js
@@ -4,8 +4,7 @@
 
 let errorHandler = require('./errorHandler');
 
-module.exports = function (app) {
-
+module.exports = function attachMiddlewares (app) {
   // Error handler middleware, define as the last one
   app.use(errorHandler);
 };
\ No newline at end of file