diff --git a/ElectronNET.Host/api/browserWindows.js b/ElectronNET.Host/api/browserWindows.js
index e251386..533ec22 100644
--- a/ElectronNET.Host/api/browserWindows.js
+++ b/ElectronNET.Host/api/browserWindows.js
@@ -266,8 +266,13 @@ module.exports = (socket, app) => {
         electronSocket.emit('browserWindow-isFocused-completed', isFocused);
     });
     socket.on('browserWindowIsDestroyed', (id) => {
-        const isDestroyed = getWindowById(id).isDestroyed();
-        electronSocket.emit('browserWindow-isDestroyed-completed', isDestroyed);
+        const w = getWindowById(id);
+        if (w) {
+            const isDestroyed = w.isDestroyed();
+            electronSocket.emit('browserWindow-isDestroyed-completed', isDestroyed);
+        } else {
+            electronSocket.emit('browserWindow-isDestroyed-completed', true);
+        }
     });
     socket.on('browserWindowShow', (id) => {
         getWindowById(id).show();
diff --git a/ElectronNET.Host/api/browserWindows.ts b/ElectronNET.Host/api/browserWindows.ts
index 6f086e2..2135b33 100644
--- a/ElectronNET.Host/api/browserWindows.ts
+++ b/ElectronNET.Host/api/browserWindows.ts
@@ -315,9 +315,13 @@ export = (socket: Socket, app: Electron.App) => {
     });
 
     socket.on('browserWindowIsDestroyed', (id) => {
-        const isDestroyed = getWindowById(id).isDestroyed();
-
-        electronSocket.emit('browserWindow-isDestroyed-completed', isDestroyed);
+        const w = getWindowById(id);
+        if (w) {
+            const isDestroyed = w.isDestroyed();
+            electronSocket.emit('browserWindow-isDestroyed-completed', isDestroyed);
+        } else {
+            electronSocket.emit('browserWindow-isDestroyed-completed', true);
+        }
     });
 
     socket.on('browserWindowShow', (id) => {