diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index fac058b..2c898c4 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -774,9 +774,11 @@
 	tty = winch->tty;
 	if (tty != NULL) {
 		line = tty->driver_data;
-		chan_window_size(&line->chan_list, &tty->winsize.ws_row,
-				 &tty->winsize.ws_col);
-		kill_pgrp(tty->pgrp, SIGWINCH, 1);
+		if (line != NULL) {
+			chan_window_size(&line->chan_list, &tty->winsize.ws_row,
+					 &tty->winsize.ws_col);
+			kill_pgrp(tty->pgrp, SIGWINCH, 1);
+		}
 	}
  out:
 	if (winch->fd != -1)