diff --git a/README.md b/README.md
index adff0ec..d87c601 100644
--- a/README.md
+++ b/README.md
@@ -76,7 +76,7 @@ $ pip install yepkit-pykush
 ```bash
 $ python pykush.py -h
 usage: pykush.py [-h] [-s SERIAL]
-                 (-l | -u [UP [UP ...]] | -d [DOWN [DOWN ...]] | -r READ | -w WRITE WRITE | -p)
+                 (-l | -u [UP [UP ...]] | -d [DOWN [DOWN ...]] | -o | -f | -r READ | -w WRITE WRITE | -p)
 
 Yepkit YKUSH command line tool.
 
@@ -92,6 +92,8 @@ optional arguments:
   -d [DOWN [DOWN ...]], --down [DOWN [DOWN ...]]
                         the downstream port numbers to power down, none means
                         all
+  -o, --power_on        switch ON 5V power output
+  -f, --power_off       switch OFF 5V power output
   -r READ, --read READ  the GPIO pin to read from
   -w WRITE WRITE, --write WRITE WRITE
                         the GPIO pin to write to
diff --git a/pykush/pykush.py b/pykush/pykush.py
index a44bdef..f60eed2 100755
--- a/pykush/pykush.py
+++ b/pykush/pykush.py
@@ -31,7 +31,7 @@
 Command line usage:
 
 	usage: pykush_hidapi.py [-h] [-s SERIAL]
-							(-l | -u [UP [UP ...]] | -d [DOWN [DOWN ...]] | -p)
+							(-l | -u [UP [UP ...]] | -d [DOWN [DOWN ...]] -o | -f | -p)
 
 	Yepkit YKUSH command line tool.
 
@@ -47,6 +47,8 @@
 	  -d [DOWN [DOWN ...]], --down [DOWN [DOWN ...]]
 							the downstream port numbers to power down, none
 							means all
+	  -o, --power_on        switch ON 5V power output
+	  -f, --power_off       switch OFF 5V power output
 	  -p, --persist         make the current running configuration persistent
 							across reboots (only supported on devices with
 							firmware v2.0 and above)