diff --git a/nextjs-app/lib/utils.ts b/nextjs-app/lib/utils.ts
index a0d1823..f052b41 100644
--- a/nextjs-app/lib/utils.ts
+++ b/nextjs-app/lib/utils.ts
@@ -383,7 +383,8 @@ export function getPhaseStyle(phase?: string | null): { key: string; label: stri
   }
 }
 
-export function formatAcademicYear(year: number): string {
+export function formatAcademicYear(year: number | null | undefined): string {
+  if (year == null) return '';
   const s = year.toString();
   if (s.length === 6) {
     return `${s.slice(0, 4)}/${s.slice(4)}`;