diff --git a/app/models/glossary_term.rb b/app/models/glossary_term.rb
index 88ea9b5..d5526e2 100644
--- a/app/models/glossary_term.rb
+++ b/app/models/glossary_term.rb
@@ -4,6 +4,21 @@ class GlossaryTerm < ActiveRecord::Base
 
   # class method from Redmine::Acts::Attachable::ClassMethods
   acts_as_attachable view_permission: :view_glossary, edit_permission: :manage_glossary, delete_permission: :manage_glossary
+
+  acts_as_event datetime: :updated_at,
+                description: :description,
+                author: nil,
+                title: Proc.new {|o| "#{l(:glossary_title)} ##{o.id} - #{o.name}" },
+                url: Proc.new {|o| { controller: 'glossary_terms',
+                                     action: 'show',
+                                     id: o.id,
+                                     project_id: o.project }
+  }
+
+  acts_as_activity_provider scope: joins(:project),
+                            type: 'glossary_terms',
+                            permission: :view_glossary,
+                            timestamp: :updated_at
   
   scope :search_by_name, -> (keyword) {
     where 'name like ?', "#{sanitize_sql_like(keyword)}%"
diff --git a/init.rb b/init.rb
index 3ecc3c6..5af0ee1 100644
--- a/init.rb
+++ b/init.rb
@@ -1,3 +1,7 @@
+#Rails.configuration.to_prepare do
+#  Redmine::Activity.register :glossary_terms
+#end
+
 Redmine::Plugin.register :redmine_glossary do
   name 'Redmine Glossary plugin'
   author 'Toru Takahashi'
@@ -26,3 +30,6 @@ Redmine::Plugin.register :redmine_glossary do
        param: :project_id
 
 end
+
+
+Redmine::Activity.register :glossary_terms