diff --git a/source/code/plugin/health/agg_monitor_id_labels.rb b/source/code/plugin/health/agg_monitor_id_labels.rb
index bb016adb4..d5c724a86 100644
--- a/source/code/plugin/health/agg_monitor_id_labels.rb
+++ b/source/code/plugin/health/agg_monitor_id_labels.rb
@@ -1,3 +1,5 @@
+require_relative 'health_model_constants'
+
 module HealthModel
     class AggregateMonitorInstanceIdLabels
         @@id_labels_mapping = {