diff --git a/core/sys/rtimer.h b/core/sys/rtimer.h
index 366cef210..49caeab12 100644
--- a/core/sys/rtimer.h
+++ b/core/sys/rtimer.h
@@ -45,7 +45,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * @(#)$Id: rtimer.h,v 1.7 2008/10/14 12:46:39 nvt-se Exp $
+ * @(#)$Id: rtimer.h,v 1.8 2008/10/14 13:27:55 nvt-se Exp $
  */
 #ifndef __RTIMER_H__
 #define __RTIMER_H__
@@ -89,14 +89,17 @@ enum {
  * \brief      Post a real-time task.
  * \param task A pointer to the task variable previously declared with RTIMER_TASK().
  * \param time The time when the task is to be executed.
+ * \param duration Unused argument.
+ * \param func A function to be called when the task is executed.
+ * \param ptr An opaque pointer that will be supplied as an argument to the callback function.
  * \return     Non-zero (true) if the task could be scheduled, zero
  *             (false) if the task could not be scheduled.
  *
- *             This function schedules a real-time task a specified
+ *             This function schedules a real-time task at a specified
  *             time in the future.
  *
  */
-int rtimer_set(struct rtimer *t, rtimer_clock_t time,
+int rtimer_set(struct rtimer *task, rtimer_clock_t time,
 	       rtimer_clock_t duration, rtimer_callback_t func, void *ptr);
 
 /**