diff --git a/src/libnm-client-impl/nm-client.c b/src/libnm-client-impl/nm-client.c
index cd5621d5cc..686c02c93c 100644
--- a/src/libnm-client-impl/nm-client.c
+++ b/src/libnm-client-impl/nm-client.c
@@ -5248,7 +5248,7 @@ _add_and_activate_connection(NMClient           *self,
  * @partial: (allow-none): an #NMConnection to add; the connection may be
  *   partially filled (or even %NULL) and will be completed by NetworkManager
  *   using the given @device and @specific_object before being added
- * @device: the #NMDevice
+ * @device: (allow-none): the #NMDevice
  * @specific_object: (allow-none): the object path of a connection-type-specific
  *   object this activation should use. This parameter is currently ignored for
  *   wired and mobile broadband connections, and the value of %NULL should be used
@@ -5322,7 +5322,7 @@ nm_client_add_and_activate_connection_finish(NMClient *client, GAsyncResult *res
  * @partial: (allow-none): an #NMConnection to add; the connection may be
  *   partially filled (or even %NULL) and will be completed by NetworkManager
  *   using the given @device and @specific_object before being added
- * @device: the #NMDevice
+ * @device: (allow-none): the #NMDevice
  * @specific_object: (allow-none): the object path of a connection-type-specific
  *   object this activation should use. This parameter is currently ignored for
  *   wired and mobile broadband connections, and the value of %NULL should be used