diff --git a/Gemfile b/Gemfile
index c326c57..3abdb01 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,7 +3,7 @@ source 'http://rubygems.org'
 gem 'rails', '~> 3.2.0'
 
 gem 'nokogiri'
-gem 'mongoid', '~> 2.2.2'
+gem 'mongoid', '~> 2.4.10'
 
 gem 'haml'
 gem 'htmlentities', "~> 4.3.0"
diff --git a/Gemfile.lock b/Gemfile.lock
index 9ee71b3..e88cd39 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -105,8 +105,8 @@ GEM
     mime-types (1.18)
     mongo (1.3.1)
       bson (>= 1.3.1)
-    mongoid (2.2.5)
-      activemodel (~> 3.0)
+    mongoid (2.4.10)
+      activemodel (~> 3.1)
       mongo (~> 1.3)
       tzinfo (~> 0.3.22)
     mongoid_rails_migrations (0.0.14)
@@ -242,7 +242,7 @@ DEPENDENCIES
   kaminari
   lighthouse-api
   mongo (= 1.3.1)
-  mongoid (~> 2.2.2)
+  mongoid (~> 2.4.10)
   mongoid_rails_migrations
   nokogiri
   octokit (= 0.6.4)
diff --git a/app/models/app.rb b/app/models/app.rb
index ffd206d..dbcfe73 100644
--- a/app/models/app.rb
+++ b/app/models/app.rb
@@ -47,7 +47,7 @@ class App
   #
   # Accepts either XML or a hash with the following attributes:
   #
-  # * <tt>:klass</tt> - the class of error
+  # * <tt>:error_class</tt> - the class of error
   # * <tt>:message</tt> - the error message
   # * <tt>:backtrace</tt> - an array of stack trace lines
   #
@@ -67,7 +67,7 @@ class App
   #
   # Accepts a hash with the following attributes:
   #
-  # * <tt>:klass</tt> - the class of error
+  # * <tt>:error_class</tt> - the class of error
   # * <tt>:message</tt> - the error message
   # * <tt>:backtrace</tt> - an array of stack trace lines
   #
diff --git a/app/models/err.rb b/app/models/err.rb
index 1988050..9863fbc 100644
--- a/app/models/err.rb
+++ b/app/models/err.rb
@@ -6,7 +6,7 @@ class Err
   include Mongoid::Document
   include Mongoid::Timestamps
 
-  field :klass
+  field :error_class
   field :component
   field :action
   field :environment
@@ -14,11 +14,11 @@ class Err
 
   belongs_to :problem
   index :problem_id
-  index :klass
+  index :error_class
 
   has_many :notices, :inverse_of => :err, :dependent => :destroy
 
-  validates_presence_of :klass, :environment
+  validates_presence_of :error_class, :environment
 
   delegate :app, :resolved?, :to => :problem
 
diff --git a/app/models/error_report.rb b/app/models/error_report.rb
index e9d4bd0..68c3aa5 100644
--- a/app/models/error_report.rb
+++ b/app/models/error_report.rb
@@ -2,7 +2,7 @@ require 'digest/md5'
 require 'hoptoad_notifier'
 
 class ErrorReport
-  attr_reader :klass, :message, :backtrace, :request, :server_environment, :api_key, :notifier, :user_attributes
+  attr_reader :error_class, :message, :backtrace, :request, :server_environment, :api_key, :notifier, :user_attributes
 
   def initialize(xml_or_attributes)
     @attributes = (xml_or_attributes.is_a?(String) ? Hoptoad.parse_xml!(xml_or_attributes) : xml_or_attributes).with_indifferent_access
@@ -36,6 +36,7 @@ class ErrorReport
   def generate_notice!
     notice = Notice.new(
       :message => message,
+      :error_class => error_class,
       :backtrace => backtrace,
       :request => request,
       :server_environment => server_environment,
@@ -43,7 +44,7 @@ class ErrorReport
       :user_attributes => user_attributes)
 
     err = app.find_or_create_err!(
-      :klass => klass,
+      :error_class => error_class,
       :component => component,
       :action => action,
       :environment => rails_env,
diff --git a/app/models/notice.rb b/app/models/notice.rb
index 4ba9e05..85cafb8 100644
--- a/app/models/notice.rb
+++ b/app/models/notice.rb
@@ -11,7 +11,7 @@ class Notice
   field :request, :type => Hash
   field :notifier, :type => Hash
   field :user_attributes, :type => Hash
-  field :klass
+  field :error_class
 
   belongs_to :err
   index :created_at
diff --git a/app/models/problem.rb b/app/models/problem.rb
index 43dae4c..4ca333f 100644
--- a/app/models/problem.rb
+++ b/app/models/problem.rb
@@ -16,7 +16,7 @@ class Problem
   field :notices_count, :type => Integer, :default => 0
   field :message
   field :environment
-  field :klass
+  field :error_class
   field :where
   field :user_agents, :type => Hash, :default => {}
   field :messages,    :type => Hash, :default => {}
@@ -128,7 +128,7 @@ class Problem
     attrs.merge!(
       :message => notice.message,
       :environment => notice.environment_name,
-      :klass => notice.klass,
+      :error_class => notice.error_class,
       :where => notice.where,
       :messages    => attribute_count_increase(:messages, notice.message),
       :hosts       => attribute_count_increase(:hosts, notice.host),
diff --git a/app/views/errs/show.html.haml b/app/views/errs/show.html.haml
index 88e20d0..cd8fe5a 100644
--- a/app/views/errs/show.html.haml
+++ b/app/views/errs/show.html.haml
@@ -1,5 +1,5 @@
 - content_for :page_title, @problem.message
-- content_for :title, @problem.klass
+- content_for :title, @problem.error_class
 - content_for :meta do
   %strong App:
   = link_to @app.name, app_path(@app)
diff --git a/app/views/notices/_summary.html.haml b/app/views/notices/_summary.html.haml
index e1c7395..2c6136c 100644
--- a/app/views/notices/_summary.html.haml
+++ b/app/views/notices/_summary.html.haml
@@ -3,6 +3,9 @@
     %tr
       %th Message
       %td.main.nowrap= message_graph(problem)
+    %tr
+      %th Error Class
+      %td= notice.error_class
     - if notice.request['url'].present?
       %tr
         %th URL
diff --git a/db/migrate/20120530005915_rename_klass_to_error_class.rb b/db/migrate/20120530005915_rename_klass_to_error_class.rb
new file mode 100644
index 0000000..8644ff2
--- /dev/null
+++ b/db/migrate/20120530005915_rename_klass_to_error_class.rb
@@ -0,0 +1,13 @@
+class RenameKlassToErrorClass < Mongoid::Migration
+  def self.up
+    [Problem, Err, Notice].each do |model|
+      model.collection.update({}, {'$rename' => {'klass' => 'error_class'}}, multi: true, safe: true)
+    end
+  end
+
+  def self.down
+    [Problem, Err, Notice].each do |model|
+      model.collection.update({}, {'$rename' => {'error_class' => 'klass'}}, multi: true, safe: true)
+    end
+  end
+end
diff --git a/lib/hoptoad/v2.rb b/lib/hoptoad/v2.rb
index 1087360..ea9ed6f 100644
--- a/lib/hoptoad/v2.rb
+++ b/lib/hoptoad/v2.rb
@@ -50,7 +50,7 @@ module Hoptoad
 
     def self.for_errbit_api(notice)
       {
-        :klass              => notice['error']['class'] || notice['error']['key'],
+        :error_class        => notice['error']['class'] || notice['error']['key'],
         :message            => notice['error']['message'],
         :backtrace          => notice['error']['backtrace']['line'],
 
diff --git a/lib/tasks/errbit/demo.rake b/lib/tasks/errbit/demo.rake
index 581ae7a..d7d32d4 100644
--- a/lib/tasks/errbit/demo.rake
+++ b/lib/tasks/errbit/demo.rake
@@ -9,22 +9,22 @@ namespace :errbit do
     app.problems.delete_all
     
     errors = [{
-      :klass => "ArgumentError",
+      :error_class => "ArgumentError",
       :message => "wrong number of arguments (3 for 0)"
     }, {
-      :klass => "RuntimeError",
+      :error_class => "RuntimeError",
       :message => "Could not find Red October"
     }, {
-      :klass => "TypeError",
+      :error_class => "TypeError",
       :message => "can't convert Symbol into Integer"
     }, {
-      :klass => "ActiveRecord::RecordNotFound",
+      :error_class => "ActiveRecord::RecordNotFound",
       :message => "could not find a record with the id 5"
     }, {
-      :klass => "NameError",
+      :error_class => "NameError",
       :message => "uninitialized constant Tag"
     }, {
-      :klass => "SyntaxError",
+      :error_class => "SyntaxError",
       :message => "unexpected tSTRING_BEG, expecting keyword_do or '{' or '('"
     }]
     
@@ -44,7 +44,7 @@ namespace :errbit do
       rand(34).times do
         
         error_report = error_template.reverse_merge({
-          :klass => "StandardError",
+          :error_class => "StandardError",
           :message => "Oops. Something went wrong!",
           :backtrace => random_backtrace,
           :request => {
diff --git a/spec/fabricators/err_fabricator.rb b/spec/fabricators/err_fabricator.rb
index 6d842c2..2b92461 100644
--- a/spec/fabricators/err_fabricator.rb
+++ b/spec/fabricators/err_fabricator.rb
@@ -1,6 +1,6 @@
 Fabricator :err do
   problem!
-  klass!         { 'FooError' }
+  error_class!         { 'FooError' }
   component     'foo'
   action        'bar'
   environment   'production'
diff --git a/spec/models/app_spec.rb b/spec/models/app_spec.rb
index 5a4e5ea..466c90c 100644
--- a/spec/models/app_spec.rb
+++ b/spec/models/app_spec.rb
@@ -117,7 +117,7 @@ describe App do
     before do
       @app = Fabricate(:app)
       @conditions = {
-        :klass        => 'Whoops',
+        :error_class  => 'Whoops',
         :component    => 'Foo',
         :action       => 'bar',
         :environment  => 'production'
@@ -158,7 +158,7 @@ describe App do
     it 'finds the correct err for the notice' do
       App.should_receive(:find_by_api_key!).and_return(@app)
       @app.should_receive(:find_or_create_err!).with({
-        :klass        => 'HoptoadTestingException',
+        :error_class  => 'HoptoadTestingException',
         :component    => 'application',
         :action       => 'verify',
         :environment  => 'development',
@@ -171,7 +171,7 @@ describe App do
     it 'marks the err as unresolved if it was previously resolved' do
       App.should_receive(:find_by_api_key!).and_return(@app)
       @app.should_receive(:find_or_create_err!).with({
-        :klass        => 'HoptoadTestingException',
+        :error_class  => 'HoptoadTestingException',
         :component    => 'application',
         :action       => 'verify',
         :environment  => 'development',
diff --git a/spec/models/err_spec.rb b/spec/models/err_spec.rb
index b12530c..55c1cf5 100644
--- a/spec/models/err_spec.rb
+++ b/spec/models/err_spec.rb
@@ -3,10 +3,10 @@ require 'spec_helper'
 describe Err do
 
   context 'validations' do
-    it 'requires a klass' do
-      err = Fabricate.build(:err, :klass => nil)
+    it 'requires a error_class' do
+      err = Fabricate.build(:err, :error_class => nil)
       err.should_not be_valid
-      err.errors[:klass].should include("can't be blank")
+      err.errors[:error_class].should include("can't be blank")
     end
 
     it 'requires an environment' do
--
libgit2 0.21.2