diff --git a/core/sys/rtimer.h b/core/sys/rtimer.h
index 49caeab12..3e1a56b1d 100644
--- a/core/sys/rtimer.h
+++ b/core/sys/rtimer.h
@@ -1,3 +1,6 @@
+/** \addtogroup sys
+ * @{ */
+
 /**
  * \defgroup rt Real-time task scheduling
  *
@@ -45,7 +48,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * @(#)$Id: rtimer.h,v 1.8 2008/10/14 13:27:55 nvt-se Exp $
+ * @(#)$Id: rtimer.h,v 1.9 2009/03/01 09:31:43 adamdunkels Exp $
  */
 #ifndef __RTIMER_H__
 #define __RTIMER_H__
@@ -147,3 +150,4 @@ void rtimer_arch_schedule(rtimer_clock_t t);
 #endif /* __RTIMER_H__ */
 
 /** @} */
+/** @} */
diff --git a/core/sys/stimer.h b/core/sys/stimer.h
index 98ed234d3..11bd1dee6 100644
--- a/core/sys/stimer.h
+++ b/core/sys/stimer.h
@@ -2,7 +2,7 @@
  * @{ */
 
 /**
- * \defgroup timer Seconds timer library
+ * \defgroup stimer Seconds timer library
  *
  * The stimer library provides functions for setting, resetting and
  * restarting timers, and for checking if a timer has expired. An
@@ -64,7 +64,7 @@
  *
  * Author: Adam Dunkels <adam@sics.se>, Nicolas Tsiftes <nvt@sics.se>
  *
- * $Id: stimer.h,v 1.2 2008/10/02 15:04:37 nvt-se Exp $
+ * $Id: stimer.h,v 1.3 2009/03/01 09:31:43 adamdunkels Exp $
  */
 #ifndef __STIMER_H__
 #define __STIMER_H__