diff --git a/lib/Models/GeoJsonCatalogItem.js b/lib/Models/GeoJsonCatalogItem.js
index <HASH>..<HASH> 100644
--- a/lib/Models/GeoJsonCatalogItem.js
+++ b/lib/Models/GeoJsonCatalogItem.js
@@ -805,6 +805,7 @@ function filterArray(pts, func) {
 
 function updateOpacity(item) {
   const entities = item.dataSource.entities.values;
+  item.dataSource.entities.suspendEvents();
   for (var i = 0; i < entities.length; i++) {
     const entity = entities[i];
 
@@ -838,6 +839,7 @@ function updateOpacity(item) {
         .withAlpha(item.opacity);
     }
   }
+  item.dataSource.entities.resumeEvents();
   item.terria.currentViewer.notifyRepaintRequired();
 }
suspend and resume events on setting geojson opacity