diff --git a/src/panel-triggers/components/AlertList/AlertCard.tsx b/src/panel-triggers/components/AlertList/AlertCard.tsx
index b893ac8..87eaf9d 100644
--- a/src/panel-triggers/components/AlertList/AlertCard.tsx
+++ b/src/panel-triggers/components/AlertList/AlertCard.tsx
@@ -72,7 +72,7 @@ export default class AlertCard extends PureComponent<AlertCardProps, AlertCardSt
     let problemColor: string;
     if (problem.value === '0') {
       problemColor = panelOptions.okEventColor;
-    } else if (panelOptions.markAckEvents && problem.acknowledges && problem.acknowledges.length) {
+    } else if (panelOptions.markAckEvents && problem.lastEvent.acknowledged === "1") {
       problemColor = panelOptions.ackEventColor;
     } else {
       problemColor = severityDesc.color;
diff --git a/src/panel-triggers/components/Problems/Problems.tsx b/src/panel-triggers/components/Problems/Problems.tsx
index 7301f8d..627d99b 100644
--- a/src/panel-triggers/components/Problems/Problems.tsx
+++ b/src/panel-triggers/components/Problems/Problems.tsx
@@ -183,7 +183,7 @@ function SeverityCell(props: RTCell<ZBXTrigger>, problemSeverityDesc: TriggerSev
   color = severityDesc.color;
 
   // Mark acknowledged triggers with different color
-  if (markAckEvents && problem.acknowledges && problem.acknowledges.length) {
+  if (markAckEvents && problem.lastEvent.acknowledged === "1") {
     color = ackEventColor;
   }