show not found error on missing slugs

web/src/app/arrangementer/[slug]/page.tsx

@@ -1,11 +1,11 @@
-import { graphql } from "@/gql";
-import { EventFragment } from "@/gql/graphql";
 import { getClient } from "@/app/client";
 import { Blocks } from "@/components/blocks/Blocks";
-import Image from "@/components/general/Image";
-import { EventHeader } from "@/components/events/EventHeader";
 import { DateList } from "@/components/events/DateList";
+import { EventHeader } from "@/components/events/EventHeader";
 import { BgPig } from "@/components/general/BgPig";
+import { graphql } from "@/gql";
+import { EventFragment } from "@/gql/graphql";
+import { notFound } from "next/navigation";
 
 export async function generateStaticParams() {
   const allEventSlugsQuery = graphql(`
@@ -42,6 +42,10 @@ export default async function Page({ params }: { params: { slug: string } }) {
     slug: params.slug,
   });
 
+  if (data?.event === null || error) {
+    return notFound();
+  }
+
   const event = (data?.event ?? {}) as EventFragment;
 
   return (