diff --git a/include/uapi/linux/tty_flags.h b/include/uapi/linux/tty_flags.h
index 6ac609a00dea..900a32e63424 100644
--- a/include/uapi/linux/tty_flags.h
+++ b/include/uapi/linux/tty_flags.h
@@ -13,7 +13,7 @@
  */
 #define ASYNCB_HUP_NOTIFY	 0 /* Notify getty on hangups and closes
 				    * on the callout port */
-#define ASYNCB_FOURPORT		 1 /* Set OU1, OUT2 per AST Fourport settings */
+#define ASYNCB_FOURPORT		 1 /* Set OUT1, OUT2 per AST Fourport settings */
 #define ASYNCB_SAK		 2 /* Secure Attention Key (Orange book) */
 #define ASYNCB_SPLIT_TERMIOS	 3 /* [x] Separate termios for dialin/callout */
 #define ASYNCB_SPD_HI		 4 /* Use 57600 instead of 38400 bps */