diff --git a/arch/um/drivers/chan_user.c b/arch/um/drivers/chan_user.c
index d8845d4aac6a7..6040817c036f3 100644
--- a/arch/um/drivers/chan_user.c
+++ b/arch/um/drivers/chan_user.c
@@ -256,7 +256,8 @@ static int winch_tramp(int fd, struct tty_port *port, int *fd_out,
 		goto out_close;
 	}
 
-	if (os_set_fd_block(*fd_out, 0)) {
+	err = os_set_fd_block(*fd_out, 0);
+	if (err) {
 		printk(UM_KERN_ERR "winch_tramp: failed to set thread_fd "
 		       "non-blocking.\n");
 		goto out_close;