diff --git a/app/observers/milestone_observer.rb b/app/observers/milestone_observer.rb
new file mode 100644
index 0000000..a1a62a9
--- /dev/null
+++ b/app/observers/milestone_observer.rb
@@ -0,0 +1,13 @@
+class MilestoneObserver < BaseObserver
+  def after_create(milestone)
+    event_service.open_milestone(milestone, current_user)
+  end
+
+  def after_close(milestone, transition)
+    event_service.close_milestone(milestone, current_user)
+  end
+
+  def after_reopen(milestone, transition)
+    event_service.reopen_milestone(milestone, current_user)
+  end
+end
--
libgit2 0.21.2