diff --git a/Gemfile b/Gemfile
index 498d8ad..a5d0e5d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -27,7 +27,7 @@ gem 'rest-client',              '~> 1.6'
 gem 'exception_notification',   '~> 4.0.1'
 gem 'gettext',                  '~> 3.1', :require => false
 gem 'locale',                   '~> 2.1'
-gem 'whenever', :require => false
+gem 'whenever',                 '~> 0.9.4', :require => false
 gem 'eita-jrails', '~> 0.10.0', require: 'jrails'
 gem 'diffy',                    '~> 3.0'
 gem 'slim'
--
libgit2 0.21.2