diff --git a/src/interfaces/utils.ts b/src/interfaces/utils.ts
index 5537734a..c8270771 100644
--- a/src/interfaces/utils.ts
+++ b/src/interfaces/utils.ts
@@ -1,5 +1,5 @@
 export function calculateAge(start: Date, end = new Date()) {
-  if (start.getTime() > end.getTime()) return;
+  if (start.getTime() > end.getTime()) return null;
 
   let year = end.getFullYear() - start.getFullYear();
   let month = end.getMonth() - start.getMonth();