diff --git a/src/indexed-db.ts b/src/indexed-db.ts
index 72299d7..7c85aeb 100644
--- a/src/indexed-db.ts
+++ b/src/indexed-db.ts
@@ -2,22 +2,50 @@ class SlopDB {
     db: IDBDatabase
 
     constructor(idb_version: number) {
+        this.open_database(idb_version).then((db) => {
+            this.db = db
+        }).catch((err) => {
+            console.log(err)
+            throw err
+        })
+    }
 
+    apply_db_upgrade(db: IDBDatabase, idb_version: number) {
+        switch (idb_version) {
+            case 1: 
+                db.createObjectStore("slop", { keyPath: "domain" })
+                break
+            case 2:
+                db.createObjectStore("checkcache", { keyPath: "domain" })
+                break
+        }
     }
 
     async open_database(idb_version: number): Promise<IDBDatabase> {
         const db_promise = new Promise<IDBDatabase>((resolve, reject) => {
             const db_request = window.indexedDB.open("SlopDB", idb_version)
 
-            db_request.onerror = (event) => {
+            db_request.onerror = (_event) => {
                 reject(db_request.error)
             }
 
-            db_request.onsuccess = (event) => {
+            db_request.onsuccess = (_event) => {
                 resolve(db_request.result)
             }
 
-            db_request.onupgradeneeded
+            db_request.onupgradeneeded = (upgrade_event) => {
+                const oldVersion = upgrade_event.oldVersion
+                const newVersion = upgrade_event.newVersion
+
+                const db = db_request.result
+
+                // make updates
+                for (let version = oldVersion + 1; version <= newVersion; version++) {
+                    this.apply_db_upgrade(db, version)
+                }
+
+                resolve(db)
+            }
         })
 
         return db_promise