diff --git a/include/linux/tty.h b/include/linux/tty.h
index 97d660ed70c19..e53e90ed3f197 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -137,6 +137,7 @@ struct tty_bufhead {
 #define C_CLOCAL(tty)	_C_FLAG((tty), CLOCAL)
 #define C_CIBAUD(tty)	_C_FLAG((tty), CIBAUD)
 #define C_CRTSCTS(tty)	_C_FLAG((tty), CRTSCTS)
+#define C_CMSPAR(tty)	_C_FLAG((tty), CMSPAR)
 
 #define L_ISIG(tty)	_L_FLAG((tty), ISIG)
 #define L_ICANON(tty)	_L_FLAG((tty), ICANON)