diff --git a/app/lib/definitions.ts b/app/lib/definitions.ts
index 3ea3fe1..572914b 100644
--- a/app/lib/definitions.ts
+++ b/app/lib/definitions.ts
@@ -47,7 +47,7 @@ export type Group = {
   guest_count: number;
   icon: string;
   children: Group[];
-  color: string;
+  color?: string;
   attendance?: AttendanceSummary
 };