diff --git a/packages/puppeteer-core/src/common/Connection.ts b/packages/puppeteer-core/src/common/Connection.ts
index a07f1e48c946f..0a5c366a7d80f 100644
--- a/packages/puppeteer-core/src/common/Connection.ts
+++ b/packages/puppeteer-core/src/common/Connection.ts
@@ -310,7 +310,8 @@ export class Connection extends EventEmitter {
       const session = new CDPSessionImpl(
         this,
         object.params.targetInfo.type,
-        sessionId
+        sessionId,
+        object.sessionId
       );
       this.#sessions.set(sessionId, session);
       this.emit('sessionattached', session);
@@ -470,6 +471,15 @@ export class CDPSession extends EventEmitter {
     throw new Error('Not implemented');
   }
 
+  /**
+   * Parent session in terms of CDP's auto-attach mechanism.
+   *
+   * @internal
+   */
+  parentSession(): CDPSession | undefined {
+    return undefined;
+  }
+
   send<T extends keyof ProtocolMapping.Commands>(
     method: T,
     ...paramArgs: ProtocolMapping.Commands[T]['paramsType']
@@ -504,21 +514,36 @@ export class CDPSessionImpl extends CDPSession {
   #targetType: string;
   #callbacks = new CallbackRegistry();
   #connection?: Connection;
+  #parentSessionId?: string;
 
   /**
    * @internal
    */
-  constructor(connection: Connection, targetType: string, sessionId: string) {
+  constructor(
+    connection: Connection,
+    targetType: string,
+    sessionId: string,
+    parentSessionId: string | undefined
+  ) {
     super();
     this.#connection = connection;
     this.#targetType = targetType;
     this.#sessionId = sessionId;
+    this.#parentSessionId = parentSessionId;
   }
 
   override connection(): Connection | undefined {
     return this.#connection;
   }
 
+  override parentSession(): CDPSession | undefined {
+    if (!this.#parentSessionId) {
+      return;
+    }
+    const parent = this.#connection?.session(this.#parentSessionId);
+    return parent ?? undefined;
+  }
+
   override send<T extends keyof ProtocolMapping.Commands>(
     method: T,
     ...paramArgs: ProtocolMapping.Commands[T]['paramsType']
diff --git a/packages/puppeteer-core/src/common/DeviceRequestPrompt.test.ts b/packages/puppeteer-core/src/common/DeviceRequestPrompt.test.ts
index d832898380044..2d45bd14d338b 100644
--- a/packages/puppeteer-core/src/common/DeviceRequestPrompt.test.ts
+++ b/packages/puppeteer-core/src/common/DeviceRequestPrompt.test.ts
@@ -36,6 +36,9 @@ class MockCDPSession extends EventEmitter {
   id() {
     return '1';
   }
+  parentSession() {
+    return undefined;
+  }
 }
 
 describe('DeviceRequestPrompt', function () {
diff --git a/packages/puppeteer-core/src/common/NetworkManager.test.ts b/packages/puppeteer-core/src/common/NetworkManager.test.ts
index 8a098f877c433..8537e7382d649 100644
--- a/packages/puppeteer-core/src/common/NetworkManager.test.ts
+++ b/packages/puppeteer-core/src/common/NetworkManager.test.ts
@@ -37,6 +37,9 @@ class MockCDPSession extends EventEmitter {
   id() {
     return '1';
   }
+  parentSession() {
+    return undefined;
+  }
 }
 
 describe('NetworkManager', () => {
diff --git a/test/TestExpectations.json b/test/TestExpectations.json
index 05a73d6bfab35..ba51e60ad2c96 100644
--- a/test/TestExpectations.json
+++ b/test/TestExpectations.json
@@ -2649,7 +2649,7 @@
     "testIdPattern": "[mouse.spec] Mouse should resize the textarea",
     "platforms": ["darwin", "linux", "win32"],
     "parameters": ["firefox", "webDriverBiDi"],
-    "expectations": ["PASS", "FAIL"]
+    "expectations": ["FAIL", "PASS"]
   },
   {
     "testIdPattern": "[mouse.spec] Mouse should select the text with mouse",