diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 2455f952e0aa..fa49529682ce 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -2588,7 +2588,8 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 			flags = *fp++;
 		switch (flags) {
 		case TTY_NORMAL:
-			gsm->receive(gsm, *cp);
+			if (gsm->receive)
+				gsm->receive(gsm, *cp);
 			break;
 		case TTY_OVERRUN:
 		case TTY_BREAK: