diff --git a/apps/web/src/global.d.ts b/apps/web/src/global.d.ts
index 15fb1e490..fb14fddbd 100644
--- a/apps/web/src/global.d.ts
+++ b/apps/web/src/global.d.ts
@@ -32,6 +32,7 @@ type DesktopIntegrationSettings = {
 };
 
 declare interface Window {
+  os: typeof process.platform & "mas";
   config: {
     static spellChecker(): Promise<SpellCheckerOptions>;
     static desktopIntegration(): Promise<DesktopIntegrationSettings>;
diff --git a/apps/web/src/utils/platform.js b/apps/web/src/utils/platform.ts
similarity index 97%
rename from apps/web/src/utils/platform.js
rename to apps/web/src/utils/platform.ts
index 670acc920..0007acc15 100644
--- a/apps/web/src/utils/platform.js
+++ b/apps/web/src/utils/platform.ts
@@ -20,7 +20,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 export function getPlatform() {
   if (window.os) return window.os;
 
-  var userAgent = window.navigator.userAgent,
+  const userAgent = window.navigator.userAgent,
     platform = window.navigator.platform,
     macosPlatforms = ["Macintosh", "MacIntel", "MacPPC", "Mac68K"],
     windowsPlatforms = ["Win32", "Win64", "Windows", "WinCE"],
@@ -42,7 +42,7 @@ export function getPlatform() {
   return os;
 }
 
-export function getDownloadLink(platform) {
+export function getDownloadLink(platform: string) {
   const baseurl = `https://notesnook.com/releases/${platform.toLowerCase()}`;
   switch (platform) {
     case "iOS":