diff --git a/src/client/DesktopShell.ts b/src/client/DesktopShell.ts
new file mode 100644
index 000000000..3c6da51ba
--- /dev/null
+++ b/src/client/DesktopShell.ts
@@ -0,0 +1,13 @@
+// The Electron desktop (Steam) shell exposes this global via a contextBridge
+// preload script — see openfront-desktop's src/preload/preload.ts. Its mere
+// presence is a reliable signal we're running inside that shell, since only
+// the desktop build's preload script ever sets it.
+declare global {
+  interface Window {
+    openfrontDesktop?: unknown;
+  }
+}
+
+export function isDesktopShell(): boolean {
+  return typeof window !== "undefined" && window.openfrontDesktop !== undefined;
+}
diff --git a/src/client/Main.ts b/src/client/Main.ts
index 39e609c8e..dc40cc090 100644
--- a/src/client/Main.ts
+++ b/src/client/Main.ts
@@ -26,6 +26,7 @@ import "./CosmeticsModal";
 import { CosmeticsModal } from "./CosmeticsModal";
 import { updateCrazyGamesNavButton } from "./CrazyGamesAccountButton";
 import { crazyGamesSDK } from "./CrazyGamesSDK";
+import { isDesktopShell } from "./DesktopShell";
 import "./FeaturedStream";
 import "./FlagInput";
 import { FlagInput } from "./FlagInput";
@@ -505,7 +506,8 @@ class Client {
       }
       const isAdFree =
         userMeResponse !== false && userMeResponse.player?.adfree === true;
-      window.adsEnabled = !isAdFree && !crazyGamesSDK.isOnCrazyGames();
+      window.adsEnabled =
+        !isAdFree && !crazyGamesSDK.isOnCrazyGames() && !isDesktopShell();
       // Ad-eligible users only: paid/adfree users must never load Admiral (its
       // adblock popup fires autonomously once the payload runs). Start watching
       // adblock state; once a blocker is ever detected the in-game ad is