diff --git a/src/client/channelOwner.ts b/src/client/channelOwner.ts
index c943d22133..91e59deabf 100644
--- a/src/client/channelOwner.ts
+++ b/src/client/channelOwner.ts
@@ -20,6 +20,7 @@ import type { Connection } from './connection';
 import type { Logger } from './types';
 import { debugLogger } from '../utils/debugLogger';
 import { rewriteErrorMessage } from '../utils/stackTrace';
+import { createScheme, Validator, ValidationError } from '../protocol/validator';
 
 export abstract class ChannelOwner<T extends channels.Channel = channels.Channel, Initializer = {}> extends EventEmitter {
   private _connection: Connection;
@@ -48,23 +49,14 @@ export abstract class ChannelOwner<T extends channels.Channel = channels.Channel
     const base = new EventEmitter();
     this._channel = new Proxy(base, {
       get: (obj: any, prop) => {
-        if (String(prop).startsWith('_'))
-          return obj[prop];
-        if (prop === 'then')
-          return obj.then;
-        if (prop === 'emit')
-          return obj.emit;
-        if (prop === 'on')
-          return obj.on;
-        if (prop === 'once')
-          return obj.once;
-        if (prop === 'addEventListener')
-          return obj.addListener;
-        if (prop === 'removeEventListener')
-          return obj.removeListener;
-        if (prop === 'domain') // https://github.com/microsoft/playwright/issues/3848
-          return obj.domain;
-        return (params: any) => this._connection.sendMessageToServer(this._type, guid, String(prop), params);
+        if (prop === 'debugScopeState')
+          return (params: any) => this._connection.sendMessageToServer(guid, prop, params);
+        if (typeof prop === 'string') {
+          const validator = scheme[paramsName(type, prop)];
+          if (validator)
+            return (params: any) => this._connection.sendMessageToServer(guid, prop, validator(params, ''));
+        }
+        return obj[prop];
       },
     });
     (this._channel as any)._object = this;
@@ -121,3 +113,17 @@ function logApiCall(logger: Logger | undefined, message: string) {
     logger.log('api', 'info', message, [], { color: 'cyan' });
   debugLogger.log('api', message);
 }
+
+function paramsName(type: string, method: string) {
+  return type + method[0].toUpperCase() + method.substring(1) + 'Params';
+}
+
+const tChannel = (name: string): Validator => {
+  return (arg: any, path: string) => {
+    if (arg._object instanceof ChannelOwner && (name === '*' || arg._object._type === name))
+      return { guid: arg._object._guid };
+    throw new ValidationError(`${path}: expected ${name}`);
+  };
+};
+
+const scheme = createScheme(tChannel);
diff --git a/src/client/connection.ts b/src/client/connection.ts
index cc0e01dc64..3efc9bf7a7 100644
--- a/src/client/connection.ts
+++ b/src/client/connection.ts
@@ -35,7 +35,6 @@ import * as channels from '../protocol/channels';
 import { ChromiumBrowser } from './chromiumBrowser';
 import { ChromiumBrowserContext } from './chromiumBrowserContext';
 import { Stream } from './stream';
-import { createScheme, Validator, ValidationError } from '../protocol/validator';
 import { WebKitBrowser } from './webkitBrowser';
 import { FirefoxBrowser } from './firefoxBrowser';
 import { debugLogger } from '../utils/debugLogger';
@@ -70,13 +69,12 @@ export class Connection {
     return this._objects.get(guid)!;
   }
 
-  async sendMessageToServer(type: string, guid: string, method: string, params: any): Promise<any> {
+  async sendMessageToServer(guid: string, method: string, params: any): Promise<any> {
     const stackObject: any = {};
     Error.captureStackTrace(stackObject);
     const stack = stackObject.stack.startsWith('Error') ? stackObject.stack.substring(5) : stackObject.stack;
     const id = ++this._lastId;
-    const validated = method === 'debugScopeState' ? params : validateParams(type, method, params);
-    const converted = { id, guid, method, params: validated };
+    const converted = { id, guid, method, params };
     // Do not include metadata in debug logs to avoid noise.
     debugLogger.log('channel:command', converted);
     this.onmessage({ ...converted, metadata: { stack } });
@@ -243,20 +241,3 @@ export class Connection {
     return result;
   }
 }
-
-const tChannel = (name: string): Validator => {
-  return (arg: any, path: string) => {
-    if (arg._object instanceof ChannelOwner && (name === '*' || arg._object._type === name))
-      return { guid: arg._object._guid };
-    throw new ValidationError(`${path}: expected ${name}`);
-  };
-};
-
-const scheme = createScheme(tChannel);
-
-function validateParams(type: string, method: string, params: any): any {
-  const name = type + method[0].toUpperCase() + method.substring(1) + 'Params';
-  if (!scheme[name])
-    throw new ValidationError(`Unknown scheme for ${type}.${method}`);
-  return scheme[name](params, '');
-}