diff --git a/app/views/timelog/_form.html.erb b/app/views/timelog/_form.html.erb
index 3a0543e7c3..87cf926f18 100644
--- a/app/views/timelog/_form.html.erb
+++ b/app/views/timelog/_form.html.erb
@@ -1,7 +1,7 @@
 <%= error_messages_for 'time_entry' %>
 <%= back_url_hidden_field_tag %>
 
-<div class="box tabular">
+<%= labelled_fields_for :time_entry, @time_entry do |f| %>
   <% if @time_entry.new_record? && params[:project_id] %>
     <%= hidden_field_tag 'project_id', params[:project_id] %>
   <% elsif @time_entry.new_record? && params[:issue_id] %>
@@ -36,7 +36,7 @@
     <% end %>
   <% end %>
   <%= call_hook(:view_timelog_edit_form_bottom, { :time_entry => @time_entry, :form => f }) %>
-</div>
+<% end %>
 
 <%= javascript_tag do %>
   $(document).ready(function(){
@@ -44,11 +44,7 @@
       $('#time_entry_issue_id').val('');
     });
     $('#time_entry_project_id, #time_entry_issue_id').change(function(){
-      $.ajax({
-        url: '<%= escape_javascript(@time_entry.new_record? ? new_time_entry_path(:format => 'js') : edit_time_entry_path(:format => 'js')) %>',
-        type: 'post',
-        data: $(this).closest('form').serialize()
-      });
+      updateTimeEntryForm('<%= escape_javascript(@time_entry.new_record? ? new_time_entry_path(:format => 'js') : edit_time_entry_path(:format => 'js')) %>');
     });
   });
 
diff --git a/app/views/timelog/edit.html.erb b/app/views/timelog/edit.html.erb
index 3cc96dfd02..5479426a4e 100644
--- a/app/views/timelog/edit.html.erb
+++ b/app/views/timelog/edit.html.erb
@@ -1,7 +1,9 @@
 <h2><%= l(:label_spent_time) %></h2>
 
-<%= labelled_form_for @time_entry, :url => time_entry_path(@time_entry), :html => {:multipart => true} do |f| %>
+<%= labelled_form_for @time_entry, :url => time_entry_path(@time_entry), :html => {:id =>'time-entry-form', :multipart => true} do |f| %>
+  <div class="box tabular" id="all_attributes">
   <%= render :partial => 'form', :locals => {:f => f} %>
+  </div>
   <%= submit_tag l(:button_save) %>
   <%= cancel_button_tag_for_time_entry(@project) %>
 <% end %>
diff --git a/app/views/timelog/edit.js.erb b/app/views/timelog/edit.js.erb
index 4cba8cfe6c..fd7a13ed6f 100644
--- a/app/views/timelog/edit.js.erb
+++ b/app/views/timelog/edit.js.erb
@@ -1,2 +1 @@
-$('#time_entry_activity_id').html('<%= escape_javascript options_for_select(activity_collection_for_select_options(@time_entry), @time_entry.activity_id) %>');
-$('#time_entry_issue').html('<%= escape_javascript link_to_issue(@time_entry.issue) if @time_entry.issue.try(:visible?) %>');
+replaceTimeEntryFormWith('<%= escape_javascript(render :partial => 'form') %>');
diff --git a/app/views/timelog/new.html.erb b/app/views/timelog/new.html.erb
index 9ec89d52ae..6941b2979a 100644
--- a/app/views/timelog/new.html.erb
+++ b/app/views/timelog/new.html.erb
@@ -1,7 +1,9 @@
 <h2><%= l(:label_spent_time) %></h2>
 
-<%= labelled_form_for @time_entry, :url => time_entries_path, :html => {:multipart => true} do |f| %>
+<%= labelled_form_for @time_entry, :url => time_entries_path, :html => {:id =>'time-entry-form', :multipart => true} do |f| %>
+  <div class="box tabular" id="all_attributes">
   <%= render :partial => 'form', :locals => {:f => f} %>
+  </div>
   <%= submit_tag l(:button_create) %>
   <%= submit_tag l(:button_create_and_continue), :name => 'continue' %>
   <%= cancel_button_tag_for_time_entry(@project) %>
diff --git a/app/views/timelog/new.js.erb b/app/views/timelog/new.js.erb
index 4cba8cfe6c..fd7a13ed6f 100644
--- a/app/views/timelog/new.js.erb
+++ b/app/views/timelog/new.js.erb
@@ -1,2 +1 @@
-$('#time_entry_activity_id').html('<%= escape_javascript options_for_select(activity_collection_for_select_options(@time_entry), @time_entry.activity_id) %>');
-$('#time_entry_issue').html('<%= escape_javascript link_to_issue(@time_entry.issue) if @time_entry.issue.try(:visible?) %>');
+replaceTimeEntryFormWith('<%= escape_javascript(render :partial => 'form') %>');
diff --git a/public/javascripts/application.js b/public/javascripts/application.js
index 5552952cd5..3e47024579 100644
--- a/public/javascripts/application.js
+++ b/public/javascripts/application.js
@@ -634,6 +634,29 @@ function updateBulkEditFrom(url) {
   });
 }
 
+function updateTimeEntryForm(url) {
+  $('#all_attributes input, #all_attributes textarea, #all_attributes select').each(function(){
+    $(this).data('valuebeforeupdate', $(this).val());
+  });
+  return $.ajax({
+    url: url,
+    type: 'post',
+    data: $('#time-entry-form').serialize()
+  });
+}
+
+function replaceTimeEntryFormWith(html){
+  var replacement = $(html);
+  $('#all_attributes input, #all_attributes textarea, #all_attributes select').each(function(){
+    var object_id = $(this).attr('id');
+    if (object_id && $(this).data('valuebeforeupdate')!=$(this).val()) {
+      replacement.find('#'+object_id).val($(this).val());
+    }
+  });
+  $('#all_attributes').empty();
+  $('#all_attributes').prepend(replacement);
+}
+
 function observeAutocompleteField(fieldId, url, options) {
   $(document).ready(function() {
     $('#'+fieldId).autocomplete($.extend({
diff --git a/test/application_system_test_case.rb b/test/application_system_test_case.rb
index a8b6f55d59..d813f0ce3e 100644
--- a/test/application_system_test_case.rb
+++ b/test/application_system_test_case.rb
@@ -81,6 +81,12 @@ class ApplicationSystemTestCase < ActionDispatch::SystemTestCase
     assert_equal '/my/page', current_path
   end
 
+  def wait_for_ajax
+    Timeout.timeout(Capybara.default_max_wait_time) do
+      loop until page.evaluate_script("jQuery.active").zero?
+    end
+  end
+
   def clear_downloaded_files
     FileUtils.rm downloaded_files
   end
diff --git a/test/functional/timelog_controller_test.rb b/test/functional/timelog_controller_test.rb
index 51fc9c3103..464d73921e 100644
--- a/test/functional/timelog_controller_test.rb
+++ b/test/functional/timelog_controller_test.rb
@@ -143,7 +143,7 @@ class TimelogControllerTest < Redmine::ControllerTest
     @request.session[:user_id] = 3
     post :new, :params => {:time_entry => {:project_id => 1}, :format => 'js'}
     assert_response :success
-    assert_include '#time_entry_activity_id', response.body
+    assert_include 'id=\"time_entry_activity_id\"', response.body
   end
 
   def test_get_edit_existing_time
diff --git a/test/system/timelog_test.rb b/test/system/timelog_test.rb
index 1761d10dc2..fdbac385cd 100644
--- a/test/system/timelog_test.rb
+++ b/test/system/timelog_test.rb
@@ -38,15 +38,44 @@ class TimelogTest < ApplicationSystemTestCase
       assert has_content?('Design')
     end
 
-    within 'form#new_time_entry' do
+    within 'form#time-entry-form' do
       select 'eCookbook', :from => 'Project'
     end
+    wait_for_ajax
     within 'select#time_entry_activity_id' do
       assert has_content?('Development')
       assert !has_content?('Design')
     end
   end
 
+  def test_changing_project_should_switch_show_or_hide_custom_fields_depending_on_roles
+    project1 = Project.find(1)  # eCookbook
+    project2 = Project.find(2)  # OnlineStore
+    project2.enable_module!(:time_tracking)
+    user = User.find(2)         # jsmith
+    assert_equal [1], user.roles_for_project(project1).collect(&:id).sort
+    assert_equal [2], user.roles_for_project(project2).collect(&:id).sort
+    custom_field = TimeEntryCustomField.find(10)  # Overtime
+    custom_field.visible = 0
+    custom_field.role_ids = [1]
+    custom_field.save!
+
+    log_user 'jsmith', 'jsmith'
+    visit '/time_entries/new'
+
+    within 'form#time-entry-form' do
+      assert has_no_content?('Overtime')
+
+      select 'eCookbook', from: 'Project'
+      wait_for_ajax
+      assert has_content?('Overtime')
+
+      select 'OnlineStore', from: 'Project'
+      wait_for_ajax
+      assert has_no_content?('Overtime')
+    end
+  end
+
   def test_bulk_edit
     log_user 'jsmith', 'jsmith'
     visit '/time_entries/bulk_edit?ids[]=1&ids[]=2&ids[]=3'