diff --git a/highcharts-ng/highcharts-ng.d.ts b/highcharts-ng/highcharts-ng.d.ts
index b429bb97d..fc0d107b9 100644
--- a/highcharts-ng/highcharts-ng.d.ts
+++ b/highcharts-ng/highcharts-ng.d.ts
@@ -17,7 +17,7 @@ interface HighChartsNGConfig {
     };
     //Boolean to control showng loading status on chart (optional)
     //Could be a string if you want to show specific loading text.
-    loading?: boolean;
+    loading?: boolean | string;
     //Configuration for the xAxis (optional). Currently only one x axis can be dynamically controlled.
     //properties currentMin and currentMax provied 2-way binding to the chart's maximimum and minimum
     xAxis?: {