diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
index 8d625390..0c12dec 100644
--- a/drivers/tty/n_hdlc.c
+++ b/drivers/tty/n_hdlc.c
@@ -614,7 +614,7 @@
 		}
 			
 		/* no data */
-		if (file->f_flags & O_NONBLOCK) {
+		if (tty_io_nonblock(tty, file)) {
 			ret = -EAGAIN;
 			break;
 		}
@@ -681,7 +681,7 @@
 		if (tbuf)
 			break;
 
-		if (file->f_flags & O_NONBLOCK) {
+		if (tty_io_nonblock(tty, file)) {
 			error = -EAGAIN;
 			break;
 		}