diff --git a/systemd_notifier.rb b/systemd_notifier.rb
index 77de16e..995ab33 100644
--- a/systemd_notifier.rb
+++ b/systemd_notifier.rb
@@ -35,9 +35,8 @@ class SystemdNotifier
     @enable_heartbeat
   end
 
-  def notify(message)
+  def self.notify(message)
     return unless @enable_heartbeat
-
     begin
       @socket.send(message, 0)
       MethodExecutor.record("debug", "heartbeat", "Heartbeat sent: #{message}")