diff --git a/website/src/pages/archive/[year]/[month]/[day]/[slug].astro b/website/src/pages/archive/[year]/[month]/[day]/[slug].astro
index 2f8bb2bc..aaf4e01b 100644
--- a/website/src/pages/archive/[year]/[month]/[day]/[slug].astro
+++ b/website/src/pages/archive/[year]/[month]/[day]/[slug].astro
@@ -11,7 +11,7 @@ export async function getStaticPaths() {
     const slug = email.frontmatter.permalink
       .replace('archive/', '')
       .replace('\n', '')
-      .split('/')[3]
+      .split('/')[3] as string
 
     return {
       params: {