diff --git a/drivers/timers/pwm.c b/drivers/timers/pwm.c
index b6b3be36a15..9e627fdcde2 100644
--- a/drivers/timers/pwm.c
+++ b/drivers/timers/pwm.c
@@ -437,9 +437,7 @@ static int pwm_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
   switch (cmd)
     {
       /* PWMIOC_SETCHARACTERISTICS - Set the characteristics of the next
-       *   pulsed output.  This command will neither start nor stop the
-       *   pulsed output.  It will either setup the configuration that will
-       *   be used when the output is started; or it will change the
+       *   pulsed output and start the pulsed output. It will change the
        *   characteristics of the pulsed output on the fly if the timer is
        *   already started.
        *
diff --git a/include/nuttx/timers/pwm.h b/include/nuttx/timers/pwm.h
index e18b9600d48..d19153e07e9 100644
--- a/include/nuttx/timers/pwm.h
+++ b/include/nuttx/timers/pwm.h
@@ -79,12 +79,10 @@
  * interface, the majority of the functionality is implemented in driver
  * ioctl calls.  The PWM ioctl commands are listed below:
  *
- * PWMIOC_SETCHARACTERISTICS - Set the characteristics of the next pulsed
- *  output.  This command will neither start nor stop the pulsed output.
- *  It will either setup the configuration that will be used when the
- *  output is started; or it will change the characteristics of the pulsed
- *  output on the fly if the timer is already started.  This command will
- *  set the PWM characteristics and return immediately.
+ * PWMIOC_SETCHARACTERISTICS - Set the characteristics of the next
+ *  pulsed output and start the pulsed output. It will change the
+ *  characteristics of the pulsed output on the fly if the timer is
+ *  already started.
  *
  *  ioctl argument: A read-only reference to struct pwm_info_s that provides
  *  the characteristics of the pulsed output.