diff --git a/doc/progs b/doc/progs
index 3014d1d2..f5af4d93 100644
--- a/doc/progs
+++ b/doc/progs
@@ -119,6 +119,10 @@ see useful_addresses.html.
   This script creates the /dev/i2c-* files. Please check the source before
   you run it, as you may need to set some variables first.
 
+* prog/pwm/pwmtest (shell script, not installed)
+  This script tests the pwm (pulse width modulation) outputs of sensors
+  for their effect on the fans.
+
 * prog/rrd/sens_update_rrd (written in bash, not installed)
   This script gathers sensors data and adds it to a round robin database
   (RRD). RRD is then used to display the graphed data in web pages.