diff --git a/packages/builder/src/components/design/AppPreview/CurrentItemPreview.svelte b/packages/builder/src/components/design/AppPreview/CurrentItemPreview.svelte
index 12f5280b83..3b827f1f34 100644
--- a/packages/builder/src/components/design/AppPreview/CurrentItemPreview.svelte
+++ b/packages/builder/src/components/design/AppPreview/CurrentItemPreview.svelte
@@ -73,7 +73,17 @@
     // Initialise the app when mounted
     iframe.contentWindow.addEventListener(
       "ready",
-      () => refreshContent(strippedJson),
+      () => {
+        loading = false
+        refreshContent(strippedJson)
+      },
+      { once: true }
+    )
+
+    // Use iframe loading event to support old client versions
+    iframe.contentWindow.addEventListener(
+      "iframe-loaded",
+      () => (loading = false),
       { once: true }
     )
 
@@ -98,7 +108,7 @@
         idToDelete = data.id
         confirmDeleteDialog.show()
       } else if (type === "preview-loaded") {
-        loading = false
+        // loading = false
       } else {
         console.warning(`Client sent unknown event type: ${type}`)
       }
diff --git a/packages/builder/src/components/design/AppPreview/iframeTemplate.js b/packages/builder/src/components/design/AppPreview/iframeTemplate.js
index 81b9a9c86f..d65916145b 100644
--- a/packages/builder/src/components/design/AppPreview/iframeTemplate.js
+++ b/packages/builder/src/components/design/AppPreview/iframeTemplate.js
@@ -64,6 +64,7 @@ export default `
           if (window.loadBudibase) {
             window.loadBudibase()
             document.documentElement.classList.add("loaded")
+            window.dispatchEvent(new Event("iframe-loaded"))
           } else {
             throw "The client library couldn't be loaded"
           }