diff --git a/src/input/rs232.c b/src/input/rs232.c
index 390d7fe..522cf0e 100644
--- a/src/input/rs232.c
+++ b/src/input/rs232.c
@@ -256,9 +256,7 @@
 	ser_handle->line = line;
 	ser_handle->delay_ms = delay_ms;
 
-	bfd->when = OSMO_FD_READ;
-	bfd->cb = serial_fd_cb;
-	bfd->data = ser_handle;
+	osmo_fd_setup(bfd, bfd->fd, OSMO_FD_READ, serial_fd_cb, ser_handle, 0);
 
 	rc = osmo_fd_register(bfd);
 	if (rc < 0) {