diff --git a/src/models/account.svelte.js b/src/models/account.svelte.ts
similarity index 65%
rename from src/models/account.svelte.js
rename to src/models/account.svelte.ts
index 5ff6466..65a98f2 100644
--- a/src/models/account.svelte.js
+++ b/src/models/account.svelte.ts
@@ -2,28 +2,26 @@ import { BlueskyAPI } from '../api/api.js';
 import { pdsEndpointForIdentifier } from '../api/identity.js';
 
 class Account {
-
-  #isIncognito;
-  #biohazardEnabled;
-  #loggedIn;
-  #avatarURL;
-  #avatarIsLoading;
+  #isIncognito: boolean;
+  #biohazardEnabled: boolean | undefined;
+  #loggedIn: boolean;
+  #avatarURL: string | undefined;
+  #avatarIsLoading: boolean;
 
   constructor() {
     let incognito = localStorage.getItem('incognito');
-    let biohazard = JSON.parse(localStorage.getItem('biohazard') ?? 'null');
+    let biohazard = localStorage.getItem('biohazard');
+    let biohazardEnabled = biohazard ? !!JSON.parse(biohazard) : undefined;
     let accountAPI = new BlueskyAPI(null, true);
 
     this.#isIncognito = $state(accountAPI.isLoggedIn && !!incognito);
-    this.#biohazardEnabled = $state(biohazard);
+    this.#biohazardEnabled = $state(biohazardEnabled);
     this.#loggedIn = $state(accountAPI.isLoggedIn);
-    this.#avatarURL = $state(accountAPI.isLoggedIn && accountAPI.user.avatar);
+    this.#avatarURL = $state(accountAPI.isLoggedIn ? accountAPI.user.avatar : undefined);
     this.#avatarIsLoading = $state(false);
   }
 
-  /** @returns {boolean} */
-
-  get isIncognito() {
+  get isIncognito(): boolean {
     return this.#isIncognito;
   }
 
@@ -37,40 +35,28 @@ class Account {
     location.reload();
   }
 
-  /** @returns {boolean?} */
-
-  get biohazardEnabled() {
+  get biohazardEnabled(): boolean | undefined {
     return this.#biohazardEnabled;
   }
 
-  /** @param {boolean} value */
-
-  set biohazardEnabled(value) {
+  set biohazardEnabled(value: boolean) {
     this.#biohazardEnabled = value;
     localStorage.setItem('biohazard', JSON.stringify(value));
   }
 
-  /** @returns {boolean} */
-
-  get loggedIn() {
+  get loggedIn(): boolean {
     return this.#loggedIn;
   }
 
-  /** @returns {string | undefined} */
-
-  get avatarURL() {
+  get avatarURL(): string | undefined {
     return this.#avatarURL;
   }
 
-  /** @returns {boolean} */
-
-  get avatarIsLoading() {
+  get avatarIsLoading(): boolean {
     return this.#avatarIsLoading;
   }
 
-  /** @param {string} identifier, @param {string} password, @returns {Promise<BlueskyAPI>} */
-
-  async logIn(identifier, password) {
+  async logIn(identifier: string, password: string): Promise<BlueskyAPI> {
     let pdsEndpoint = await pdsEndpointForIdentifier(identifier);
 
     let pdsAPI = new BlueskyAPI(pdsEndpoint, true);
@@ -80,7 +66,7 @@ class Account {
     this.#avatarIsLoading = true;
 
     pdsAPI.loadCurrentUserAvatar().then(url => {
-      this.#avatarURL = url;
+      this.#avatarURL = url || undefined;
     }).catch(error => {
       console.log(error);
     }).finally(() => {
diff --git a/src/utils/paginator.js b/src/utils/paginator.ts
similarity index 63%
rename from src/utils/paginator.js
rename to src/utils/paginator.ts
index 3400ff4..9dd0428 100644
--- a/src/utils/paginator.js
+++ b/src/utils/paginator.ts
@@ -1,21 +1,16 @@
-/** @type {() => void} */
-let scrollHandler;
+let scrollHandler: (() => void) | undefined;
+let resizeObserver: ResizeObserver | undefined;
 
-/** @type {ResizeObserver} */
-let resizeObserver;
-
-export function loadInPages(callback) {
+export function loadInPages(callback: (next: () => void) => void) {
   if (scrollHandler) {
     document.removeEventListener('scroll', scrollHandler);
   }
 
-  if (resizeObserver) {
-    resizeObserver.disconnect();
-  }
+  resizeObserver?.disconnect();
 
   scrollHandler = () => {
     if (window.pageYOffset + window.innerHeight > document.body.offsetHeight - 500) {
-      callback(scrollHandler);
+      callback(scrollHandler!);
     }
   };