diff --git a/public/latest_commit b/public/latest_commit
index 6ab709b..386583d 100644
--- a/public/latest_commit
+++ b/public/latest_commit
@@ -1 +1 @@
-2f2a5s
\ No newline at end of file
+DEVELOPMENT
\ No newline at end of file
diff --git a/src/main.ts b/src/main.ts
index 5c9990c..26354e5 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -59,4 +59,9 @@ import { log } from './utils';
     Globals.GameMaster.changeScene(new MainScene());
     let params = new URLSearchParams(location.href);
     if (params.entries().next().value[1] == 'game') Globals.GameMaster.changeScene(new GameScene('Mission 1'));
+
+    if (Globals.latestCommit != 'DEVELOPMENT')
+        window.onbeforeunload = () => {
+            return 'You are about to leave.';
+        };
 })();