diff --git a/Gemfile b/Gemfile
index 7bfac1b15..876ff1e07 100644
--- a/Gemfile
+++ b/Gemfile
@@ -35,6 +35,7 @@ gem 'foundation-rails'
 gem 'foundation_rails_helper'
 gem 'acts_as_votable'
 gem 'ckeditor', '~> 4.1.5'
+gem 'invisible_captcha'
 gem 'cancancan'
 gem 'social-share-button', git: 'https://github.com/huacnlee/social-share-button.git', ref: 'e46a6a3e82b86023bc'
 gem 'initialjs-rails', '0.2.0.1'
diff --git a/Gemfile.lock b/Gemfile.lock
index 8bc02c6ce..6502986af 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -202,6 +202,8 @@ GEM
       terminal-table (>= 1.5.1)
     initialjs-rails (0.2.0.1)
       railties (>= 3.1, < 5.0)
+    invisible_captcha (0.8.1)
+      rails
     jquery-rails (4.1.1)
       rails-dom-testing (>= 1, < 3)
       railties (>= 4.2.0)
@@ -467,6 +469,7 @@ DEPENDENCIES
   groupdate
   i18n-tasks
   initialjs-rails (= 0.2.0.1)
+  invisible_captcha
   jquery-rails
   jquery-ui-rails
   kaminari