diff --git a/core/server/models/base.js b/core/server/models/base.js
index c96c85f62e69..e23e17de2fa9 100644
--- a/core/server/models/base.js
+++ b/core/server/models/base.js
@@ -85,7 +85,9 @@ ghostBookshelf.Model = ghostBookshelf.Model.extend({
         var self = this;
 
         _.each(attrs, function (value, key) {
-            if (value !== null && schema.tables[self.tableName][key].type === 'dateTime') {
+            if (value !== null
+                    && schema.tables[self.tableName].hasOwnProperty(key)
+                    && schema.tables[self.tableName][key].type === 'dateTime') {
                 // convert dateTime value into a native javascript Date object
                 attrs[key] = moment(value).toDate();
             }
@@ -98,7 +100,8 @@ ghostBookshelf.Model = ghostBookshelf.Model.extend({
     fixBools: function (attrs) {
         var self = this;
         _.each(attrs, function (value, key) {
-            if (schema.tables[self.tableName][key].type === 'bool') {
+            if (schema.tables[self.tableName].hasOwnProperty(key)
+                    && schema.tables[self.tableName][key].type === 'bool') {
                 attrs[key] = value ? true : false;
             }
         });
diff --git a/core/server/models/user.js b/core/server/models/user.js
index 28530c19825b..979ba2b1b44e 100644
--- a/core/server/models/user.js
+++ b/core/server/models/user.js
@@ -301,7 +301,8 @@ User = ghostBookshelf.Model.extend({
     edit: function (data, options) {
         var self = this,
             adminRole,
-            ownerRole;
+            ownerRole,
+            roleId;
 
         options = options || {};
         options.withRelated = _.union([ 'roles' ], options.include);
@@ -309,6 +310,7 @@ User = ghostBookshelf.Model.extend({
         return ghostBookshelf.Model.edit.call(this, data, options).then(function (user) {
 
             if (data.roles) {
+                roleId = parseInt(data.roles[0].id || data.roles[0], 10);
 
                 if (user.id === options.context.user) {
                     return when.reject(new errors.ValidationError('You are not allowed to assign a new role to yourself'));
@@ -316,7 +318,14 @@ User = ghostBookshelf.Model.extend({
                 if (data.roles.length > 1) {
                     return when.reject(new errors.ValidationError('Only one role per user is supported at the moment.'));
                 }
-                return Role.findOne({id: data.roles[0].id || data.roles[0]}).then(function (role) {
+
+                return user.roles().fetch().then(function (roles) {
+                    // return if the role is already assigned
+                    if (roles.models[0].id === roleId) {
+                        return user;
+                    }
+                    return Role.findOne({id: roleId});
+                }).then(function (role) {
                     if (role && role.get('name') === 'Owner') {
                         // Get admin and owner role
                         return Role.findOne({name: 'Administrator'}).then(function (result) {
@@ -339,7 +348,7 @@ User = ghostBookshelf.Model.extend({
                         });
                     } else {
                         // assign all other roles
-                        return user.roles().updatePivot({role_id: data.roles[0].id || data.roles[0]});
+                        return user.roles().updatePivot({role_id: roleId});
                     }
                 }).then(function () {
                     return self.findOne(user, options);