diff --git a/OPENAPI_VERSION b/OPENAPI_VERSION
index ec25eb302..eaf5acec6 100644
--- a/OPENAPI_VERSION
+++ b/OPENAPI_VERSION
@@ -1 +1 @@
-v211
\ No newline at end of file
+v212
\ No newline at end of file
diff --git a/lib/BillingPortal/Session.php b/lib/BillingPortal/Session.php
index 2f737c373..243e845bb 100644
--- a/lib/BillingPortal/Session.php
+++ b/lib/BillingPortal/Session.php
@@ -27,6 +27,7 @@
  * @property string|\Stripe\BillingPortal\Configuration $configuration The configuration used by this session, describing the features available.
  * @property int $created Time at which the object was created. Measured in seconds since the Unix epoch.
  * @property string $customer The ID of the customer for this session.
+ * @property null|\Stripe\StripeObject $flow Information about a specific flow for the customer to go through.
  * @property bool $livemode Has the value <code>true</code> if the object exists in live mode or the value <code>false</code> if the object exists in test mode.
  * @property null|string $locale The IETF language tag of the locale Customer Portal is displayed in. If blank or auto, the customer’s <code>preferred_locales</code> or browser’s locale is used.
  * @property null|string $on_behalf_of The account for which the session was created on behalf of. When specified, only subscriptions and invoices with this <code>on_behalf_of</code> account appear in the portal. For more information, see the <a href="https://stripe.com/docs/connect/charges-transfers#on-behalf-of">docs</a>. Use the <a href="https://stripe.com/docs/api/accounts/object#account_object-settings-branding">Accounts API</a> to modify the <code>on_behalf_of</code> account's branding settings, which the portal displays.