diff --git a/lib/online_status_tracker.rb b/lib/online_status_tracker.rb
index 8688c4251..ec5f65812 100644
--- a/lib/online_status_tracker.rb
+++ b/lib/online_status_tracker.rb
@@ -1,5 +1,6 @@
 module OnlineStatusTracker
-  PRESENCE_DURATION = 20.seconds
+  # NOTE: You can customise the environment variable to keep your agents/contacts as online for longer
+  PRESENCE_DURATION = ENV.fetch('PRESENCE_DURATION', 20).to_i.seconds
 
   # presence : sorted set with timestamp as the score & object id as value