diff --git a/docs/src/api/class-browsertype.md b/docs/src/api/class-browsertype.md
index 8ab2e63f8b7e9..f970d4aef3d39 100644
--- a/docs/src/api/class-browsertype.md
+++ b/docs/src/api/class-browsertype.md
@@ -324,11 +324,13 @@ this context will automatically close the browser.
 * since: v1.8
 - `userDataDir` <[path]>
 
-Path to a User Data Directory, which stores browser session data like cookies and local storage. More details for
+Path to a User Data Directory, which stores browser session data like cookies and local storage. Pass an empty string to create a temporary directory.
+
+More details for
 [Chromium](https://chromium.googlesource.com/chromium/src/+/master/docs/user_data_dir.md#introduction) and
-[Firefox](https://wiki.mozilla.org/Firefox/CommandLineOptions#User_profile).
-Note that Chromium's user data directory is the **parent** directory of the "Profile Path" seen at `chrome://version`. Pass an empty string to
-use a temporary directory instead.
+[Firefox](https://wiki.mozilla.org/Firefox/CommandLineOptions#User_profile). Chromium's user data directory is the **parent** directory of the "Profile Path" seen at `chrome://version`.
+
+Note that browsers do not allow launching multiple instances with the same User Data Directory.
 
 ### option: BrowserType.launchPersistentContext.-inline- = %%-shared-browser-options-list-v1.8-%%
 * since: v1.8
diff --git a/packages/playwright-client/types/types.d.ts b/packages/playwright-client/types/types.d.ts
index 1573308b562d5..da5df0f346832 100644
--- a/packages/playwright-client/types/types.d.ts
+++ b/packages/playwright-client/types/types.d.ts
@@ -14710,11 +14710,15 @@ export interface BrowserType<Unused = {}> {
    * Launches browser that uses persistent storage located at
    * [`userDataDir`](https://playwright.dev/docs/api/class-browsertype#browser-type-launch-persistent-context-option-user-data-dir)
    * and returns the only context. Closing this context will automatically close the browser.
-   * @param userDataDir Path to a User Data Directory, which stores browser session data like cookies and local storage. More details for
+   * @param userDataDir Path to a User Data Directory, which stores browser session data like cookies and local storage. Pass an empty
+   * string to create a temporary directory.
+   *
+   * More details for
    * [Chromium](https://chromium.googlesource.com/chromium/src/+/master/docs/user_data_dir.md#introduction) and
-   * [Firefox](https://wiki.mozilla.org/Firefox/CommandLineOptions#User_profile). Note that Chromium's user data
-   * directory is the **parent** directory of the "Profile Path" seen at `chrome://version`. Pass an empty string to use
-   * a temporary directory instead.
+   * [Firefox](https://wiki.mozilla.org/Firefox/CommandLineOptions#User_profile). Chromium's user data directory is the
+   * **parent** directory of the "Profile Path" seen at `chrome://version`.
+   *
+   * Note that browsers do not allow launching multiple instances with the same User Data Directory.
    * @param options
    */
   launchPersistentContext(userDataDir: string, options?: {
diff --git a/packages/playwright-core/types/types.d.ts b/packages/playwright-core/types/types.d.ts
index 1573308b562d5..da5df0f346832 100644
--- a/packages/playwright-core/types/types.d.ts
+++ b/packages/playwright-core/types/types.d.ts
@@ -14710,11 +14710,15 @@ export interface BrowserType<Unused = {}> {
    * Launches browser that uses persistent storage located at
    * [`userDataDir`](https://playwright.dev/docs/api/class-browsertype#browser-type-launch-persistent-context-option-user-data-dir)
    * and returns the only context. Closing this context will automatically close the browser.
-   * @param userDataDir Path to a User Data Directory, which stores browser session data like cookies and local storage. More details for
+   * @param userDataDir Path to a User Data Directory, which stores browser session data like cookies and local storage. Pass an empty
+   * string to create a temporary directory.
+   *
+   * More details for
    * [Chromium](https://chromium.googlesource.com/chromium/src/+/master/docs/user_data_dir.md#introduction) and
-   * [Firefox](https://wiki.mozilla.org/Firefox/CommandLineOptions#User_profile). Note that Chromium's user data
-   * directory is the **parent** directory of the "Profile Path" seen at `chrome://version`. Pass an empty string to use
-   * a temporary directory instead.
+   * [Firefox](https://wiki.mozilla.org/Firefox/CommandLineOptions#User_profile). Chromium's user data directory is the
+   * **parent** directory of the "Profile Path" seen at `chrome://version`.
+   *
+   * Note that browsers do not allow launching multiple instances with the same User Data Directory.
    * @param options
    */
   launchPersistentContext(userDataDir: string, options?: {