diff --git a/samples/bluetooth/hci_uart_async/prj.conf b/samples/bluetooth/hci_uart_async/prj.conf
index 1de1a46535e..9c5b79a9606 100644
--- a/samples/bluetooth/hci_uart_async/prj.conf
+++ b/samples/bluetooth/hci_uart_async/prj.conf
@@ -23,3 +23,6 @@ CONFIG_BT_BUF_EVT_DISCARDABLE_SIZE=255
 # in case it has a interfering default. Those same boards set this
 # config and it must be undone or the build will fail.
 CONFIG_UART_CONSOLE=n
+
+# reduce RAM usage
+CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=512