diff --git a/Documentation/NuttxPortingGuide.html b/Documentation/NuttxPortingGuide.html
index 285bbac213..f1ac98246d 100644
--- a/Documentation/NuttxPortingGuide.html
+++ b/Documentation/NuttxPortingGuide.html
@@ -2569,7 +2569,7 @@ int up_timer_gettime(FAR struct timespec *ts);
 int up_timer_cancel(FAR struct timespec *ts);
 </ul>
 <p><b>Description</b>:</p>
-  Cancel the interval timer and return the time remaining on the timer. These two steps need to be as nearly atomic as possible. <code>up_timer_expiration()</code> will not be called unless the timer is restarted with <code>up_timer_start()</code>. If, as a race condition, the timer has already expired when this function is called, then that pending interrupt must be cleared so that <code>up_timer_expiration()</code> is not called spuriously and the remaining time of zero should be returned.
+  Cancel the interval timer and return the time remaining on the timer. These two steps need to be as nearly atomic as possible. <code>sched_timer_expiration()</code> will not be called unless the timer is restarted with <code>up_timer_start()</code>. If, as a race condition, the timer has already expired when this function is called, then that pending interrupt must be cleared so that <code>sched_timer_expiration()</code> is not called spuriously and the remaining time of zero should be returned.
 <ul>
 </ul>
 <p><b>Input Parameters</b>:</p>
@@ -2592,12 +2592,12 @@ int up_timer_cancel(FAR struct timespec *ts);
 int up_timer_start(FAR const struct timespec *ts);
 </ul>
 <p><b>Description</b>:</p>
-  Start the interval timer. <code>up_timer_expiration()</code> will be called at the completion of the timeout (unless <code>up_timer_cancel()</code> is called to stop the timing).
+  Start the interval timer. <code>sched_timer_expiration()</code> will be called at the completion of the timeout (unless <code>up_timer_cancel()</code> is called to stop the timing).
 <ul>
 </ul>
 <p><b>Input Parameters</b>:</p>
 <ul>
-  <li><code>ts</code>: Provides the time interval until <code>up_timer_expiration()</code> is called.</li>
+  <li><code>ts</code>: Provides the time interval until <code>sched_timer_expiration()</code> is called.</li>
 </ul>
 <p><b>Returned Value</b>:</p>
 <ul>
diff --git a/arch/sim/src/up_tickless.c b/arch/sim/src/up_tickless.c
index 4e04cd71e2..68158f4341 100644
--- a/arch/sim/src/up_tickless.c
+++ b/arch/sim/src/up_tickless.c
@@ -178,8 +178,8 @@ int up_timer_gettime(FAR struct timespec *ts)
  * Description:
  *   Cancel the interval timer and return the time remaining on the timer.
  *   These two steps need to be as nearly atomic as possible.
- *   up_timer_expiration() will not be called unless the timer is restarted
- *   with up_timer_start().
+ *   sched_timer_expiration() will not be called unless the timer is
+ *   restarted with up_timer_start().
  *
  *   If, as a race condition, the timer has already expired when this
  *   function is called, then that pending interrupt must be cleared so
@@ -231,14 +231,15 @@ int up_timer_cancel(FAR struct timespec *ts)
  * Name: up_timer_start
  *
  * Description:
- *   Start the interval timer.  up_timer_expiration() will be called at the
- *   completion of the timeout (unless up_timer_cancel is called to stop
- *   the timing.
+ *   Start the interval timer.  sched_timer_expiration() will be
+ *   called at the completion of the timeout (unless up_timer_cancel
+ *   is called to stop the timing.
  *
  *   Provided by platform-specific code and called from the RTOS base code.
  *
  * Input Parameters:
- *   ts - Provides the time interval until up_timer_expiration() is called.
+ *   ts - Provides the time interval until sched_timer_expiration() is
+ *        called.
  *
  * Returned Value:
  *   Zero (OK) is returned on success; a negated errno value is returned on
diff --git a/include/nuttx/arch.h b/include/nuttx/arch.h
index 6d7cfbc62a..5a7ee87e65 100644
--- a/include/nuttx/arch.h
+++ b/include/nuttx/arch.h
@@ -1034,8 +1034,8 @@ int up_timer_gettime(FAR struct timespec *ts);
  * Description:
  *   Cancel the interval timer and return the time remaining on the timer.
  *   These two steps need to be as nearly atomic as possible.
- *   up_timer_expiration() will not be called unless the timer is restarted
- *   with up_timer_start().
+ *   sched_timer_expiration() will not be called unless the timer is
+ *   restarted with up_timer_start().
  *
  *   If, as a race condition, the timer has already expired when this
  *   function is called, then that pending interrupt must be cleared so
@@ -1067,14 +1067,15 @@ int up_timer_cancel(FAR struct timespec *ts);
  * Name: up_timer_start
  *
  * Description:
- *   Start the interval timer.  up_timer_expiration() will be called at the
- *   completion of the timeout (unless up_timer_cancel is called to stop
+ *   Start the interval timer.  sched_timer_expiration() will be called at
+ *   the completion of the timeout (unless up_timer_cancel is called to stop
  *   the timing.
  *
  *   Provided by platform-specific code and called from the RTOS base code.
  *
  * Input Parameters:
- *   ts - Provides the time interval until up_timer_expiration() is called.
+ *   ts - Provides the time interval until sched_timer_expiration() is
+ *        called.
  *
  * Returned Value:
  *   Zero (OK) is returned on success; a negated errno value is returned on