diff --git a/routes/api/feeds/[seriesId]/[episodeId]/chapters.ts b/routes/api/feeds/[seriesId]/[episodeId]/chapters.ts
index d0f317d..67c273d 100644
--- a/routes/api/feeds/[seriesId]/[episodeId]/chapters.ts
+++ b/routes/api/feeds/[seriesId]/[episodeId]/chapters.ts
@@ -2,11 +2,15 @@ import { FreshContext } from "$fresh/server.ts";
 import { parse, toSeconds } from "https://esm.sh/iso8601-duration@2.1.1";
 import { nrkRadio, OriginalEpisode } from "../../../../../lib/nrk.ts";
 
-// TODO: This type `OriginalEpisode` is missing stuff.
-function toChapters(episode: OriginalEpisode) {
+type Chapter = {
+  title: string | undefined;
+  startTime: number | undefined;
+};
+
+function toChapters(episode: OriginalEpisode): Chapter[] {
   return episode.indexPoints.map((indexPoint) => ({
     title: indexPoint.title,
-    startTime: toSeconds(parse(indexPoint.startPoint)),
+    startTime: indexPoint.startPoint ? toSeconds(parse(indexPoint.startPoint)) : undefined,
   }));
 }