diff --git a/lib/objectCache.ts b/lib/objectCache.ts
index a8b02ff..6174a69 100644
--- a/lib/objectCache.ts
+++ b/lib/objectCache.ts
@@ -43,11 +43,11 @@ class ObjectCacheService {
       const dbName = `${DB_PREFIX}${objectType}`
       const request = indexedDB.open(dbName, DB_VERSION)
 
-      request.onerror = () => {
+      request.onerror = (): void => {
         reject(new Error(`Failed to open IndexedDB: ${request.error}`))
       }
 
-      request.onsuccess = () => {
+      request.onsuccess = (): void => {
         const db = request.result
         this.dbs.set(objectType, db)
         resolve(db)