diff --git a/app/controllers/public/account_controller.rb b/app/controllers/public/account_controller.rb
index 0f63ce8..926b4d5 100644
--- a/app/controllers/public/account_controller.rb
+++ b/app/controllers/public/account_controller.rb
@@ -1,5 +1,7 @@
 class AccountController < PublicController
 
+  inverse_captcha :field => 'e_mail'
+
   # say something nice, you goof!  something sweet.
   def index
     unless logged_in?
@@ -39,7 +41,7 @@ class AccountController < PublicController
       @user = User.new(params[:user])
       @user.terms_of_use = environment.terms_of_use
       @terms_of_use = environment.terms_of_use
-      if request.post? && answer_correct
+      if request.post? && params[self.icaptcha_field].blank? && answer_correct
         @user.save!
         @user.person.environment = environment
         @user.person.save!
diff --git a/app/views/account/signup.rhtml b/app/views/account/signup.rhtml
index 15ef1c8..32aaef7 100644
--- a/app/views/account/signup.rhtml
+++ b/app/views/account/signup.rhtml
@@ -24,6 +24,8 @@
     :help => help=_('We need to be sure that you wrote correctly your password.') %>
 <small><%= help %></small>
 
+<%= icaptcha_field() %>
+
 <% if @terms_of_use %>
   <p>
     <%= @terms_of_use %>
diff --git a/test/functional/account_controller_test.rb b/test/functional/account_controller_test.rb
index aeb5032..ac6c075 100644
--- a/test/functional/account_controller_test.rb
+++ b/test/functional/account_controller_test.rb
@@ -400,6 +400,17 @@ class AccountControllerTest < Test::Unit::TestCase
 
   end
 
+  should 'not be able to signup while inverse captcha field filled' do
+    assert_no_difference User, :count do
+      create_user({}, @controller.icaptcha_field => 'bli@bla.email.foo')
+    end
+  end
+
+  should 'render inverse captcha field' do
+    get :signup
+    assert_tag :tag => 'input', :attributes => { :type => 'text', :name => @controller.icaptcha_field }
+  end
+
   protected
     def create_user(options = {}, extra_options ={})
       post :signup, { :user => { :login => 'quire',
--
libgit2 0.21.2