diff --git a/data/src/emulator.js b/data/src/emulator.js
index ca74f56..58e70c2 100644
--- a/data/src/emulator.js
+++ b/data/src/emulator.js
@@ -1159,6 +1159,11 @@ class EmulatorJS {
             }, 0);
         });
         this.addEventListener(window, "beforeunload", (e) => {
+            if (window.EJS_askBeforeUnload) {
+                e.preventDefault();
+                e.returnValue = '';
+                return
+            } 
             if (!this.started) return;
             this.callEvent("exit");
         });
diff --git a/index.html b/index.html
index f6e02bd..44e5785 100644
--- a/index.html
+++ b/index.html
@@ -259,6 +259,7 @@
                 window.EJS_DEBUG_XX = enableDebug;
                 window.EJS_disableDatabases = true;
                 window.EJS_threads = enableThreads;
+                window.EJS_askBeforeUnload = false;
                 if (browserMode) {
                     window.EJS_browserMode = browserMode;
                 }