diff --git a/spec/api-browser-window-spec.ts b/spec/api-browser-window-spec.ts
index 540ad42d14e..5f0466b16c0 100644
--- a/spec/api-browser-window-spec.ts
+++ b/spec/api-browser-window-spec.ts
@@ -2343,7 +2343,7 @@ describe('BrowserWindow module', () => {
 
       expect(w.isAlwaysOnTop()).to.be.false();
       expect(c.isAlwaysOnTop()).to.be.true('child is not always on top');
-      expect((c as any)._getAlwaysOnTopLevel()).to.equal('screen-saver');
+      expect(c._getAlwaysOnTopLevel()).to.equal('screen-saver');
     });
   });
 
diff --git a/spec/api-debugger-spec.ts b/spec/api-debugger-spec.ts
index 057f39e4184..1e63bd9c2a9 100644
--- a/spec/api-debugger-spec.ts
+++ b/spec/api-debugger-spec.ts
@@ -64,7 +64,7 @@ describe('debugger module', () => {
       });
       await detach;
       expect(w.webContents.debugger.isAttached()).to.be.false();
-      expect((w as any).devToolsWebContents.isDestroyed()).to.be.false();
+      expect(w.devToolsWebContents.isDestroyed()).to.be.false();
     });
   });
 
@@ -119,9 +119,9 @@ describe('debugger module', () => {
       w.webContents.debugger.sendCommand('Console.enable');
       const [,, params] = await message;
       w.webContents.debugger.detach();
-      expect((params as any).message.level).to.equal('log');
-      expect((params as any).message.url).to.equal(url);
-      expect((params as any).message.text).to.equal('a');
+      expect(params.message.level).to.equal('log');
+      expect(params.message.url).to.equal(url);
+      expect(params.message.text).to.equal('a');
     });
 
     it('returns error message when command fails', async () => {
diff --git a/spec/api-ipc-spec.ts b/spec/api-ipc-spec.ts
index 57491ed5708..873511b6ea3 100644
--- a/spec/api-ipc-spec.ts
+++ b/spec/api-ipc-spec.ts
@@ -239,7 +239,7 @@ describe('ipc module', () => {
       const p = once(ipcMain, 'port');
       await w.webContents.executeJavaScript(`(${function () {
         const channel = new MessageChannel();
-        (channel.port2 as any).onmessage = (ev: any) => {
+        channel.port2.onmessage = (ev: any) => {
           channel.port2.postMessage(ev.data * 2);
         };
         require('electron').ipcRenderer.postMessage('port', '', [channel.port1]);
@@ -280,7 +280,7 @@ describe('ipc module', () => {
       w2.loadURL('about:blank');
       w1.webContents.executeJavaScript(`(${function () {
         const channel = new MessageChannel();
-        (channel.port2 as any).onmessage = (ev: any) => {
+        channel.port2.onmessage = (ev: any) => {
           require('electron').ipcRenderer.send('message received', ev.data);
         };
         require('electron').ipcRenderer.postMessage('port', '', [channel.port1]);
@@ -306,7 +306,7 @@ describe('ipc module', () => {
             ipcRenderer.on('port', e => {
               const [port] = e.ports;
               port.start();
-              (port as any).onclose = () => {
+              port.onclose = () => {
                 ipcRenderer.send('closed');
               };
             });
@@ -322,9 +322,9 @@ describe('ipc module', () => {
           w.loadURL('about:blank');
           await w.webContents.executeJavaScript(`(${async function () {
             const { port2 } = new MessageChannel();
-            await new Promise(resolve => {
+            await new Promise<void>(resolve => {
               port2.start();
-              (port2 as any).onclose = resolve;
+              port2.onclose = resolve;
               process._linkedBinding('electron_common_v8_util').requestGarbageCollectionForTesting();
             });
           }})()`);
@@ -336,9 +336,9 @@ describe('ipc module', () => {
           ipcMain.once('do-a-gc', () => v8Util.requestGarbageCollectionForTesting());
           await w.webContents.executeJavaScript(`(${async function () {
             const { port1, port2 } = new MessageChannel();
-            await new Promise(resolve => {
+            await new Promise<void>(resolve => {
               port2.start();
-              (port2 as any).onclose = resolve;
+              port2.onclose = resolve;
               require('electron').ipcRenderer.postMessage('nobody-listening', null, [port1]);
               require('electron').ipcRenderer.send('do-a-gc');
             });
diff --git a/spec/api-web-contents-spec.ts b/spec/api-web-contents-spec.ts
index 089523c9537..dc9b2e6161a 100644
--- a/spec/api-web-contents-spec.ts
+++ b/spec/api-web-contents-spec.ts
@@ -1911,7 +1911,7 @@ describe('webContents module', () => {
     it('does not crash when called via BrowserWindow', () => {
       const w = new BrowserWindow({ show: false });
 
-      (w as any).setBackgroundThrottling(true);
+      w.setBackgroundThrottling(true);
     });
 
     it('does not crash when disallowing', () => {
@@ -1946,11 +1946,11 @@ describe('webContents module', () => {
     it('works via BrowserWindow', () => {
       const w = new BrowserWindow({ show: false });
 
-      (w as any).setBackgroundThrottling(false);
-      expect((w as any).getBackgroundThrottling()).to.equal(false);
+      w.setBackgroundThrottling(false);
+      expect(w.getBackgroundThrottling()).to.equal(false);
 
-      (w as any).setBackgroundThrottling(true);
-      expect((w as any).getBackgroundThrottling()).to.equal(true);
+      w.setBackgroundThrottling(true);
+      expect(w.getBackgroundThrottling()).to.equal(true);
     });
   });
 
diff --git a/spec/chromium-spec.ts b/spec/chromium-spec.ts
index 9216038dfdf..f39526df5ae 100644
--- a/spec/chromium-spec.ts
+++ b/spec/chromium-spec.ts
@@ -2012,13 +2012,13 @@ describe('chromium features', () => {
         const w = new BrowserWindow({ show: false });
         await w.loadFile(path.join(fixturesPath, 'pages', 'blank.html'));
         // History should have current page by now.
-        expect((w.webContents as any).length()).to.equal(1);
+        expect(w.webContents.length()).to.equal(1);
 
         const waitCommit = once(w.webContents, 'navigation-entry-committed');
         w.webContents.executeJavaScript('window.history.pushState({}, "")');
         await waitCommit;
         // Initial page + pushed state.
-        expect((w.webContents as any).length()).to.equal(2);
+        expect(w.webContents.length()).to.equal(2);
       });
     });
 
@@ -2038,7 +2038,7 @@ describe('chromium features', () => {
           once(w.webContents, 'did-navigate-in-page')
         ]);
 
-        (w.webContents as any).once('navigation-entry-committed', () => {
+        w.webContents.once('navigation-entry-committed' as any, () => {
           expect.fail('Unexpected navigation-entry-committed');
         });
         w.webContents.once('did-navigate-in-page', () => {
@@ -2046,7 +2046,7 @@ describe('chromium features', () => {
         });
         await w.webContents.mainFrame.frames[0].executeJavaScript('window.history.back()');
         expect(await w.webContents.executeJavaScript('window.history.state')).to.equal(1);
-        expect((w.webContents as any).getActiveIndex()).to.equal(1);
+        expect(w.webContents.getActiveIndex()).to.equal(1);
       });
     });
   });
diff --git a/typings/internal-ambient.d.ts b/typings/internal-ambient.d.ts
index 26cff6bc760..1805f58de46 100644
--- a/typings/internal-ambient.d.ts
+++ b/typings/internal-ambient.d.ts
@@ -291,6 +291,12 @@ declare interface Window {
   trustedTypes: TrustedTypePolicyFactory;
 }
 
+// https://github.com/electron/electron/blob/main/docs/tutorial/message-ports.md#extension-close-event
+
+interface MessagePort {
+  onclose: () => void;
+}
+
 // https://w3c.github.io/webappsec-trusted-types/dist/spec/#trusted-types
 
 type TrustedHTML = string;
diff --git a/typings/internal-electron.d.ts b/typings/internal-electron.d.ts
index af6be190c34..c21a42aece4 100644
--- a/typings/internal-electron.d.ts
+++ b/typings/internal-electron.d.ts
@@ -32,6 +32,8 @@ declare namespace Electron {
     _setEscapeTouchBarItem: (item: TouchBarItemType | {}) => void;
     _refreshTouchBarItem: (itemID: string) => void;
     _getWindowButtonVisibility: () => boolean;
+    _getAlwaysOnTopLevel: () => string;
+    devToolsWebContents: WebContents;
     frameName: string;
     on(event: '-touch-bar-interaction', listener: (event: Event, itemID: string, details: any) => void): this;
     removeListener(event: '-touch-bar-interaction', listener: (event: Event, itemID: string, details: any) => void): this;