diff --git a/client/src/Components/common/charts/HeatmapResponseTimeTooltip.tsx b/client/src/Components/common/charts/HeatmapResponseTimeTooltip.tsx
index dc36ee5d9..8bc651c8c 100644
--- a/client/src/Components/common/charts/HeatmapResponseTimeTooltip.tsx
+++ b/client/src/Components/common/charts/HeatmapResponseTimeTooltip.tsx
@@ -58,7 +58,7 @@ export const HeatmapResponseTimeTooltip = ({
 					</Typography>
 					<Typography>
 						{t("common.labels.responseTime")}:{" "}
-						{check?.originalResponseTime?.toFixed() ?? "-"} ms
+						{check?.originalResponseTime?.toFixed() ?? "N/A"} ms
 					</Typography>
 					<Typography textTransform={"capitalize"}>
 						Status:{" "}
diff --git a/server/src/utils/dataUtils.ts b/server/src/utils/dataUtils.ts
index 3c86c911e..f6d877a35 100755
--- a/server/src/utils/dataUtils.ts
+++ b/server/src/utils/dataUtils.ts
@@ -45,7 +45,7 @@ export const NormalizeData = <T extends HasResponseTime>(checks: T[], rangeMin:
 		const min = calculatePercentile(checks, 0);
 		const max = calculatePercentile(checks, 95);
 		const normalizedChecks = checks.map((check) => {
-			const originalResponseTime = check.responseTime;
+			const originalResponseTime = typeof check.responseTime === "number" ? check.responseTime : 0;
 			let normalizedResponseTime = rangeMin + ((check.responseTime - min) * (rangeMax - rangeMin)) / (max - min);
 
 			normalizedResponseTime = Math.max(rangeMin, Math.min(rangeMax, normalizedResponseTime));
@@ -59,7 +59,8 @@ export const NormalizeData = <T extends HasResponseTime>(checks: T[], rangeMin:
 		return normalizedChecks;
 	} else {
 		return checks.map((check) => {
-			return { ...check, originalResponseTime: check.responseTime };
+			const originalResponseTime = typeof check.responseTime === "number" ? check.responseTime : 0;
+			return { ...check, originalResponseTime: originalResponseTime };
 		});
 	}
 };