diff --git a/lib/Controllers/list.js b/lib/Controllers/list.js
index 5bd435f..2cee086 100644
--- a/lib/Controllers/list.js
+++ b/lib/Controllers/list.js
@@ -3,7 +3,8 @@
 var util = require('util'),
     Base = require('./base'),
     _ = require('lodash'),
-    errors = require('../Errors');
+    errors = require('../Errors'),
+    getKeys = require('../util').keys;
 
 var List = function(args) {
   List.super_.call(this, args);
@@ -34,7 +35,6 @@ List.prototype._safeishParse = function(value, type, sequelize) {
   }
 };
 
-var stringOperators = /like|iLike|notLike|notILike/;
 List.prototype.fetch = function(req, res, context) {
   var self = this,
       model = this.model,
@@ -47,6 +47,10 @@ List.prototype.fetch = function(req, res, context) {
       count = +context.count || +req.query.count || defaultCount,
       offset = +context.offset || +req.query.offset || 0;
 
+  var stringOperators = [
+    Sequelize.Op.like, Sequelize.Op.iLike, Sequelize.Op.notLike, Sequelize.Op.notILike,
+  ];
+
   // only look up attributes we care about
   options.attributes = options.attributes || this.resource.attributes;
 
@@ -71,11 +75,11 @@ List.prototype.fetch = function(req, res, context) {
     var searchParam = searchData.param;
     if (_.has(req.query, searchParam)) {
       var search = [];
-      var searchOperator = searchData.operator || '$like';
+      var searchOperator = searchData.operator || Sequelize.Op.like;
       var searchAttributes =
-        searchData.attributes || Object.keys(model.rawAttributes);
+        searchData.attributes || getKeys(model.rawAttributes);
       searchAttributes.forEach(function(attr) {
-        if(stringOperators.test(searchOperator)){
+        if(stringOperators.indexOf(searchOperator) !== -1){
           var attrType = model.rawAttributes[attr].type;
           if (!(attrType instanceof Sequelize.STRING) &&
               !(attrType instanceof Sequelize.TEXT)) {
@@ -89,7 +93,7 @@ List.prototype.fetch = function(req, res, context) {
         var item = {};
         var query = {};
         var searchString;
-        if (!~searchOperator.toLowerCase().indexOf('like')) {
+        if (searchOperator !== Sequelize.Op.like) {
           searchString = req.query[searchParam];
         } else {
           searchString = '%' + req.query[searchParam] + '%';
@@ -98,8 +102,8 @@ List.prototype.fetch = function(req, res, context) {
         item[attr] = query;
         search.push(item);
       });
-
-      if (Object.keys(criteria).length)
+      
+      if (getKeys(criteria).length)
         criteria = Sequelize.and(criteria, Sequelize.or.apply(null, search));
       else
         criteria = Sequelize.or.apply(null, search);
@@ -122,7 +126,7 @@ List.prototype.fetch = function(req, res, context) {
         order.push([sortColumn, 'ASC']);
       }
     });
-    var allowedColumns = this.resource.sort.attributes || Object.keys(model.rawAttributes);
+    var allowedColumns = this.resource.sort.attributes || getKeys(model.rawAttributes);
     var disallowedColumns = _.difference(columnNames, allowedColumns);
     if (disallowedColumns.length) {
       throw new errors.BadRequestError('Sorting not allowed on given attributes', disallowedColumns);
@@ -138,11 +142,11 @@ List.prototype.fetch = function(req, res, context) {
     return result;
   }, {});
 
-  if (Object.keys(extraSearchCriteria).length)
+  if (getKeys(extraSearchCriteria).length)
     criteria = _.assign(criteria, extraSearchCriteria);
 
   // do the actual lookup
-  if (Object.keys(criteria).length)
+  if (getKeys(criteria).length)
     options.where = criteria;
 
   if (req.query.scope) {
diff --git a/lib/Controllers/read.js b/lib/Controllers/read.js
index 3f4dc1a..4b468f5 100644
--- a/lib/Controllers/read.js
+++ b/lib/Controllers/read.js
@@ -2,7 +2,8 @@
 
 var util = require('util'),
     Base = require('./base'),
-    errors = require('../Errors');
+    errors = require('../Errors'),
+    getKeys = require('../util').keys;
 
 var Read = function(args) {
   Read.super_.call(this, args);
@@ -26,12 +27,12 @@ Read.prototype.fetch = function(req, res, context) {
   options.attributes = options.attributes || this.resource.attributes;
 
   // remove params that are already accounted for in criteria
-  Object.keys(criteria).forEach(function(attr) { delete req.params[attr]; });
+  getKeys(criteria).forEach(function(attr) { delete req.params[attr]; });
   endpoint.attributes.forEach(function(attribute) {
     if (attribute in req.params) criteria[attribute] = req.params[attribute];
   });
 
-  if (Object.keys(criteria).length) {
+  if (getKeys(criteria).length) {
     options.where = criteria;
   }
 
diff --git a/lib/Controllers/update.js b/lib/Controllers/update.js
index 14db168..323da82 100644
--- a/lib/Controllers/update.js
+++ b/lib/Controllers/update.js
@@ -3,7 +3,8 @@
 var _ = require('lodash'),
     util = require('util'),
     Base = require('./base'),
-    ReadController = require('./read');
+    ReadController = require('./read'),
+    getKeys = require('../util').keys;
 
 var Update = function(args) {
   if (args.resource.updateMethod)
@@ -49,7 +50,7 @@ Update.prototype.write = function(req, res, context) {
 
   // check if reload is needed
   var reloadAfter = self.resource.reloadInstances &&
-    Object.keys(self.resource.associationsInfo).some(function(attr) {
+    getKeys(self.resource.associationsInfo).some(function(attr) {
       return instance._changed.hasOwnProperty(attr);
     });
 
diff --git a/lib/Resource.js b/lib/Resource.js
index 2e95689..78633eb 100644
--- a/lib/Resource.js
+++ b/lib/Resource.js
@@ -5,7 +5,8 @@ var Controllers = require('./Controllers'),
     hasManyResource = require('./associations/has-many'),
     belongsToResource = require('./associations/belongs-to'),
     belongsToManyResource = require('./associations/belongs-to-many'),
-    _ = require('lodash');
+    _ = require('lodash'),
+    getKeys = require('./util').keys;
 
 var Resource = function(options) {
   _.defaults(options, {
@@ -41,8 +42,8 @@ var Resource = function(options) {
     this.excludeAttributes = options.excludeAttributes;
     if (_.isArray(options.excludeAttributes)) {
       this.attributes = (!options.excludeAttributes.length) ?
-        Object.keys(this.model.rawAttributes) :
-        Object.keys(this.model.rawAttributes).filter(function(attr) {
+        getKeys(this.model.rawAttributes) :
+        getKeys(this.model.rawAttributes).filter(function(attr) {
           return options.excludeAttributes.indexOf(attr) === -1;
         });
     } else if (_.isObject(options.excludeAttributes)) {
@@ -55,8 +56,8 @@ var Resource = function(options) {
       });
       if (_.has(options.excludeAttributes, "own") && _.isArray(options.excludeAttributes.own)) {
         this.attributes = (!options.excludeAttributes.own.length) ?
-          Object.keys(this.model.rawAttributes) :
-          Object.keys(this.model.rawAttributes).filter(function(attr) {
+          getKeys(this.model.rawAttributes) :
+          getKeys(this.model.rawAttributes).filter(function(attr) {
             return options.excludeAttributes.own.indexOf(attr) === -1;
           });
         // backward compatible and not breaking other stuff!
@@ -64,7 +65,7 @@ var Resource = function(options) {
       }
 
     } else {
-      this.attributes = Object.keys(this.model.rawAttributes);
+      this.attributes = getKeys(this.model.rawAttributes);
     }
   }
   
@@ -211,7 +212,7 @@ function autoAssociate(resource) {
         && _.isArray(resource.associationOptions[association.as].excludeAttributes)) {
         assocAttr = (!resource.associationOptions[association.as].excludeAttributes.length) ?
           association.target.rawAttributes :
-          Object.keys(association.target.rawAttributes).filter(function(attr) {
+          getKeys(association.target.rawAttributes).filter(function(attr) {
             return resource.associationOptions[association.as].excludeAttributes.indexOf(attr) === -1;
           });
       }
diff --git a/lib/util.js b/lib/util.js
new file mode 100644
index 0000000..e004676
--- /dev/null
+++ b/lib/util.js
@@ -0,0 +1,15 @@
+'use strict';
+
+function keys(obj) {
+  if (typeof Reflect === 'object') {
+    return Reflect.ownKeys(obj);
+  }
+  else {
+    var getOwnExists = typeof Object.getOwnPropertySymbols === 'function' && typeof Object.getOwnPropertyNames === 'function';
+    return getOwnExists ? Object.getOwnPropertyNames(obj).concat(Object.getOwnPropertySymbols(obj)) : Object.keys(obj);
+  }
+}
+
+module.exports = {
+  keys: keys
+};
diff --git a/package.json b/package.json
index 0311c6b..04eab9d 100644
--- a/package.json
+++ b/package.json
@@ -47,7 +47,7 @@
     "mocha": "^2.2.5",
     "request": "^2.60.0",
     "restify": "^4.0.3",
-    "sequelize": "^3.5.1",
+    "sequelize": "^4.15.0",
     "sqlite3": "^3.0.9"
   }
 }
diff --git a/tests/util.test.js b/tests/util.test.js
new file mode 100644
index 0000000..a606b1a
--- /dev/null
+++ b/tests/util.test.js
@@ -0,0 +1,27 @@
+'use strict';
+
+var util = require('../lib/util');
+var expect = require('chai').expect;
+
+describe('Util', function () {
+  describe('keys()', function() {
+    it("should return a simple object's keys", function () {
+      expect(util.keys({some: 'value'})).to.deep.equal(['some']);
+      expect(util.keys({some: 'value', an: 'other value'})).to.deep.equal(['some', 'an']);
+    });
+    
+    it("should return an object's symbol keys", function () {
+      var obj = {};
+      var symbol = Symbol('a_symbol');
+      obj[symbol] = 'a value';
+      expect(util.keys(obj)).to.deep.equal([symbol]);
+    });
+    
+    it("should mix string and symbol keys", function () {
+      var obj = {some: 'value'};
+      var symbol = Symbol('a_symbol');
+      obj[symbol] = 'a value';
+      expect(util.keys(obj)).to.deep.equal(['some', symbol]);
+    });
+  });
+});