diff --git a/app/models/environment.rb b/app/models/environment.rb
index 3d8f050..3ab5bef 100644
--- a/app/models/environment.rb
+++ b/app/models/environment.rb
@@ -310,7 +310,7 @@ class Environment < ActiveRecord::Base
 
   settings_items :signup_welcome_screen_body, :type => String
 
-  #Captcha setings
+  #Captcha settings
   settings_items :api_captcha_settings, :type => ActiveSupport::HashWithIndifferentAccess, :default => {}
 
   def has_custom_welcome_screen?
diff --git a/lib/noosfero/api/helpers.rb b/lib/noosfero/api/helpers.rb
index 00936d2..3176076 100644
--- a/lib/noosfero/api/helpers.rb
+++ b/lib/noosfero/api/helpers.rb
@@ -202,7 +202,6 @@
       def period(from_date, until_date)
         begin_period = from_date.nil? ? Time.at(0).to_datetime : from_date
         end_period = until_date.nil? ? DateTime.now : until_date
-
         begin_period..end_period
       end
 
@@ -211,7 +210,6 @@
       ##########################################
 
       def test_captcha(remote_ip, params, _environment = nil)
-        binding.pry
         environment ||= _environment
         d = environment.api_captcha_settings
         return true unless d[:enabled] == true
@@ -219,19 +217,20 @@
         if d[:provider] == 'google'
           raise ArgumentError, "Environment api_captcha_settings private_key not defined" if d[:private_key].nil?
           raise ArgumentError, "Environment api_captcha_settings version not defined" unless d[:version] == 1 || d[:version] == 2
-          raise ArgumentError, "Environment api_captcha_settings verify_uri not defined" if d[:verify_uri].nil?
           if d[:version]  == 1
+            d[:verify_uri] ||= 'https://www.google.com/recaptcha/api/verify'
             return verify_recaptcha_v1(remote_ip, d[:private_key], d[:verify_uri], params[:recaptcha_challenge_field], params[:recaptcha_response_field])
           end
           if d[:version] == 2
+            d[:verify_uri] ||= 'https://www.google.com/recaptcha/api/siteverify'
             return verify_recaptcha_v2(remote_ip, d[:private_key], d[:verify_uri], params[:g_recaptcha_response])
           end
         end
 
         if d[:provider] == 'serpro'
-          return verify_serpro_captcha(d[:serpro_client_id], params[:txtToken_captcha_serpro_gov_br], params[:captcha_text])
+          d[:verify_uri] ||= 'http://captcha.servicoscorporativos.serpro.gov.br'
+          return verify_serpro_captcha(d[:serpro_client_id], params[:txtToken_captcha_serpro_gov_br], params[:captcha_text], d[:verify_uri])
         end
-
         raise ArgumentError, "Environment api_captcha_settings provider not defined"
       end
 
@@ -256,7 +255,6 @@
       end
 
       def verify_recaptcha_v2(remote_ip, private_key, api_recaptcha_verify_uri, g_recaptcha_response)
-
         if g_recaptcha_response == nil
           return _('Missing captcha data')
         end
@@ -275,8 +273,7 @@
         captcha_result["success"] ? true : captcha_result
       end
 
-      def verify_serpro_captcha(client_id, token, captcha_text)
-        verify_uri = 'http://homcaptcha.servicoscorporativos.serpro.gov.br/captchavalidar/1.0.0/validar'
+      def verify_serpro_captcha(client_id, token, captcha_text, verify_uri)
         if token == nil || captcha_text == nil
           return _('Missing captcha data')
         end
diff --git a/lib/noosfero/api/session.rb b/lib/noosfero/api/session.rb
index f3adc32..56a0a54 100644
--- a/lib/noosfero/api/session.rb
+++ b/lib/noosfero/api/session.rb
@@ -41,7 +41,7 @@ module Noosfero
         attrs = attributes_for_keys [:email, :login, :password, :password_confirmation] + environment.signup_person_fields
         remote_ip = (request.respond_to?(:remote_ip) && request.remote_ip) || (env && env['REMOTE_ADDR'])
 
-        unless test_captcha(remote_ip, params) === true
+        if test_captcha(remote_ip, params, environment) != true
           render_api_error!(_('Please solve the test in order to register.'), 401)
           return
         end
diff --git a/test/unit/api/helpers_test.rb b/test/unit/api/helpers_test.rb
index 1217741..f9815af 100644
--- a/test/unit/api/helpers_test.rb
+++ b/test/unit/api/helpers_test.rb
@@ -163,7 +163,8 @@ class APIHelpersTest < ActiveSupport::TestCase
 
   should 'do not test captcha when there are no settings' do
     environment = Environment.new
-    assert test_captcha("127.0.0.1", {}, environment)
+    stubs(:environment).returns(environment)
+    assert test_captcha("127.0.0.1", {})
   end
 
   should 'do not test captcha when captcha is disabled on settings' do
@@ -171,10 +172,10 @@ class APIHelpersTest < ActiveSupport::TestCase
     environment.api_captcha_settings = {
         enabled: false,
     }
-    assert   test_captcha("127.0.0.1", {}, environment)
+    stubs(:environment).returns(environment)
+    assert test_captcha("127.0.0.1", {})
   end
 
-
   should 'fail display recaptcha v1' do
     environment = Environment.new
     environment.api_captcha_settings = {
@@ -185,7 +186,8 @@ class APIHelpersTest < ActiveSupport::TestCase
         public_key:   '6LdsWAcTAAAAAChTUUD6yu9fCDhdIZzNd7F53zf-',
         verify_uri:   'https://www.google.com/recaptcha/api/verify',
     }
-    assert_equal test_captcha("127.0.0.1", {}, environment), "Missing captcha data"
+    stubs(:environment).returns(environment)
+    assert_equal test_captcha("127.0.0.1", {}), "Missing captcha data"
   end
 
   should 'fail display recaptcha v2' do
@@ -198,7 +200,19 @@ class APIHelpersTest < ActiveSupport::TestCase
         public_key:   '6LdsWAcTAAAAAChTUUD6yu9fCDhdIZzNd7F53zf-',
         verify_uri:   'https://www.google.com/recaptcha/api/siteverify',
     }
-    assert_equal test_captcha("127.0.0.1", {}, environment), "Missing captcha data"
+    stubs(:environment).returns(environment)
+    assert_equal test_captcha("127.0.0.1", {}), "Missing captcha data"
+  end
+
+  should 'fail display Serpro captcha' do
+    environment = Environment.new
+    environment.api_captcha_settings = {
+        enabled: true,
+        provider: 'serpro',
+        serpro_client_id:  '0000000000000000',
+    }
+    stubs(:environment).returns(environment)
+    assert_equal test_captcha("127.0.0.1", {}), "Missing captcha data"
   end
 
   protected
--
libgit2 0.21.2