diff --git a/OPENAPI_VERSION b/OPENAPI_VERSION
index 1f7b99f73..e02bb288e 100644
--- a/OPENAPI_VERSION
+++ b/OPENAPI_VERSION
@@ -1 +1 @@
-v163
\ No newline at end of file
+v164
\ No newline at end of file
diff --git a/lib/Transfer.php b/lib/Transfer.php
index fed09bb97..0d8eea668 100644
--- a/lib/Transfer.php
+++ b/lib/Transfer.php
@@ -33,7 +33,7 @@
  * @property \Stripe\Collection<\Stripe\TransferReversal> $reversals A list of reversals that have been applied to the transfer.
  * @property bool $reversed Whether the transfer has been fully reversed. If the transfer is only partially reversed, this attribute will still be false.
  * @property null|string|\Stripe\Charge $source_transaction ID of the charge or payment that was used to fund the transfer. If null, the transfer was funded from the available balance.
- * @property null|string $source_type The source balance this transfer came from. One of <code>card</code>, <code>fpx</code>, or <code>bank_account</code>.
+ * @property string $source_type The source balance this transfer came from. One of <code>card</code>, <code>fpx</code>, or <code>bank_account</code>.
  * @property null|string $transfer_group A string that identifies this transaction as part of a group. See the <a href="https://stripe.com/docs/connect/charges-transfers#transfer-options">Connect documentation</a> for details.
  */
 class Transfer extends ApiResource