diff --git a/Documentation/ABI/obsolete/sysfs-gpio b/Documentation/ABI/obsolete/sysfs-gpio
index 8203bc2128db..480316fee6d8 100644
--- a/Documentation/ABI/obsolete/sysfs-gpio
+++ b/Documentation/ABI/obsolete/sysfs-gpio
@@ -22,6 +22,7 @@ Description:
 	    /value ... always readable, writes fail for input GPIOs
 	    /direction ... r/w as: in, out (default low); write: high, low
 	    /edge ... r/w as: none, falling, rising, both
+	    /active_low ... r/w as: 0, 1
 	/gpiochipN ... for each gpiochip; #N is its first GPIO
 	    /base ... (r/o) same as N
 	    /label ... (r/o) descriptive, not necessarily unique