From 03f78791980a35086fae6488b52d76e01d20690e Mon Sep 17 00:00:00 2001
From: Barry Pollard <barrypollard@google.com>
Date: Mon, 24 Aug 2026 09:16:42 +0100
Subject: [PATCH] Guard supportedEntryTypes

---
 src/lib/softNavs.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lib/softNavs.ts b/src/lib/softNavs.ts
index 2f1a135e..03f87662 100644
--- a/src/lib/softNavs.ts
+++ b/src/lib/softNavs.ts
@@ -19,7 +19,7 @@ import type {ReportOpts} from '../types.js';
 export const checkSoftNavsEnabled = (opts?: ReportOpts) => {
   return (
     // Firefox has a preference to disable this, which some people use so add a guard
-    globalThis.PerformanceObserver?.supportedEntryTypes.includes(
+    globalThis.PerformanceObserver?.supportedEntryTypes?.includes(
       'soft-navigation',
     ) &&
     // Older implementations expose the value as an attribute rather than the