diff --git a/lib/devise/strategies/authenticatable.rb b/lib/devise/strategies/authenticatable.rb
index b1062e3a..9108e727 100644
--- a/lib/devise/strategies/authenticatable.rb
+++ b/lib/devise/strategies/authenticatable.rb
@@ -105,7 +105,7 @@ module Devise
       # Helper to decode credentials from HTTP.
       def decode_credentials
         return [] unless request.authorization && request.authorization =~ /^Basic (.*)/m
-        ActiveSupport::Base64.decode64($1).split(/:/, 2)
+        Base64.decode64($1).split(/:/, 2)
       end
 
       # Sets the authentication hash and the password from params_auth_hash or http_auth_hash.
diff --git a/test/integration/http_authenticatable_test.rb b/test/integration/http_authenticatable_test.rb
index c42abb93..408483d2 100644
--- a/test/integration/http_authenticatable_test.rb
+++ b/test/integration/http_authenticatable_test.rb
@@ -4,7 +4,7 @@ class HttpAuthenticationTest < ActionController::IntegrationTest
   test 'handles unverified requests gets rid of caches but continues signed in' do
     swap UsersController, :allow_forgery_protection => true do
       create_user
-      post exhibit_user_url(1), {}, "HTTP_AUTHORIZATION" => "Basic #{ActiveSupport::Base64.encode64("user@test.com:123456")}"
+      post exhibit_user_url(1), {}, "HTTP_AUTHORIZATION" => "Basic #{Base64.encode64("user@test.com:123456")}"
       assert warden.authenticated?(:user)
       assert_equal "User is authenticated", response.body
     end
@@ -74,7 +74,7 @@ class HttpAuthenticationTest < ActionController::IntegrationTest
     token = "token_containing_so_many_characters_that_the_base64_encoding_will_wrap"
     user = create_user
     user.update_attribute :authentication_token, token
-    get users_path(:format => :xml), {}, "HTTP_AUTHORIZATION" => "Basic #{ActiveSupport::Base64.encode64("#{token}:x")}"
+    get users_path(:format => :xml), {}, "HTTP_AUTHORIZATION" => "Basic #{Base64.encode64("#{token}:x")}"
     assert_response :success
     assert_match "<email>user@test.com</email>", response.body
     assert warden.authenticated?(:user)
@@ -84,14 +84,14 @@ class HttpAuthenticationTest < ActionController::IntegrationTest
 
     def sign_in_as_new_user_with_http(username="user@test.com", password="123456")
       user = create_user
-      get users_path(:format => :xml), {}, "HTTP_AUTHORIZATION" => "Basic #{ActiveSupport::Base64.encode64("#{username}:#{password}")}"
+      get users_path(:format => :xml), {}, "HTTP_AUTHORIZATION" => "Basic #{Base64.encode64("#{username}:#{password}")}"
       user
     end
 
     # Sign in with oauth2 token. This is just to test that it isn't misinterpreted as basic authentication
     def add_oauth2_header
       user = create_user
-      get users_path(:format => :xml), {}, "HTTP_AUTHORIZATION" => "OAuth #{ActiveSupport::Base64.encode64("#{user.email}:123456")}"
+      get users_path(:format => :xml), {}, "HTTP_AUTHORIZATION" => "OAuth #{Base64.encode64("#{user.email}:123456")}"
     end
 
 end
diff --git a/test/integration/token_authenticatable_test.rb b/test/integration/token_authenticatable_test.rb
index a6e54f4c..f2ccc8ac 100644
--- a/test/integration/token_authenticatable_test.rb
+++ b/test/integration/token_authenticatable_test.rb
@@ -125,7 +125,7 @@ class TokenAuthenticationTest < ActionController::IntegrationTest
       options[:auth_token]     ||= user.authentication_token
 
       if options[:http_auth]
-        header = "Basic #{ActiveSupport::Base64.encode64("#{VALID_AUTHENTICATION_TOKEN}:X")}"
+        header = "Basic #{Base64.encode64("#{VALID_AUTHENTICATION_TOKEN}:X")}"
         get users_path(:format => :xml), {}, "HTTP_AUTHORIZATION" => header
       else
         visit users_path(options[:auth_token_key].to_sym => options[:auth_token])