diff --git a/src/lib/initMetric.ts b/src/lib/initMetric.ts
index d61ed9cc..4691db72 100644
--- a/src/lib/initMetric.ts
+++ b/src/lib/initMetric.ts
@@ -31,7 +31,7 @@ export const initMetric = (name: Metric['name'], value?: number): Metric => {
       navigationType = 'prerender';
     } else if (document.wasDiscarded) {
       navigationType = 'restore';
-    } else {
+    } else if (navEntry.type) {
       navigationType = navEntry.type.replace(
         /_/g,
         '-'