diff --git a/core/net/mac/contikimac.c b/core/net/mac/contikimac.c
index 910981ca7..d9cbf25f5 100644
--- a/core/net/mac/contikimac.c
+++ b/core/net/mac/contikimac.c
@@ -28,7 +28,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: contikimac.c,v 1.43 2010/12/07 23:12:54 adamdunkels Exp $
+ * $Id: contikimac.c,v 1.44 2010/12/10 13:36:06 adamdunkels Exp $
  */
 
 /**
@@ -315,12 +315,14 @@ powercycle(struct rtimer *t, void *ptr)
 {
   PT_BEGIN(&pt);
 
+  cycle_start = RTIMER_NOW();
+
   while(1) {
     static uint8_t packet_seen;
     static rtimer_clock_t t0;
     static uint8_t count;
 
-    cycle_start = RTIMER_NOW();
+    cycle_start += CYCLE_TIME;
 
     if(WITH_STREAMING && is_streaming) {
 #if NURTIMER