diff --git a/site/source/hooks/useIframeResizer.ts b/site/source/hooks/useIframeResizer.ts
index c4ae5436c..c9686fa72 100644
--- a/site/source/hooks/useIframeResizer.ts
+++ b/site/source/hooks/useIframeResizer.ts
@@ -1,11 +1,23 @@
 import { useEffect } from 'react'
 
+function isIframe() {
+	try {
+		return window.self !== window.top
+	} catch (e) {
+		return true
+	}
+}
+
 export function useIframeResizer() {
 	useEffect(() => {
 		// The code below communicate with the iframe.js script on a host site
 		// to automatically resize the iframe when its inner content height
 		// change.
 
+		if (!isIframe()) {
+			return
+		}
+
 		const minHeight = 700 // Also used in iframe.js
 		const observer = new ResizeObserver(([entry]) => {
 			const value = Math.max(minHeight, entry.contentRect.height)
diff --git a/site/source/pages/integration/Iframe.tsx b/site/source/pages/integration/Iframe.tsx
index 24f8de9d1..b4416d0b7 100644
--- a/site/source/pages/integration/Iframe.tsx
+++ b/site/source/pages/integration/Iframe.tsx
@@ -65,11 +65,7 @@ function IntegrationCustomizer() {
 		window.addEventListener(
 			'message',
 			function (evt: MessageEvent<{ kind: string; value: string }>) {
-				if (
-					iframeRef.current &&
-					evt.data.kind === 'resize-height' &&
-					iframeRef.current.contentDocument?.readyState === 'complete'
-				) {
+				if (iframeRef.current && evt.data.kind === 'resize-height') {
 					iframeRef.current.style.height = evt.data.value + 'px'
 				}
 			}