diff --git a/tools/cooja/apps/mspsim/src/se/sics/cooja/mspmote/MspMote.java b/tools/cooja/apps/mspsim/src/se/sics/cooja/mspmote/MspMote.java
index e951e75fd..782cc75a1 100644
--- a/tools/cooja/apps/mspsim/src/se/sics/cooja/mspmote/MspMote.java
+++ b/tools/cooja/apps/mspsim/src/se/sics/cooja/mspmote/MspMote.java
@@ -26,7 +26,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: MspMote.java,v 1.9 2008/09/17 12:09:20 fros4943 Exp $
+ * $Id: MspMote.java,v 1.10 2008/09/17 17:39:37 nifi Exp $
  */
 
 package se.sics.cooja.mspmote;
@@ -53,6 +53,7 @@ public abstract class MspMote implements Mote {
 
   /* Cycle counter */
   public long cycleCounter = 0;
+  public int cycleDrift = 0;
 
   private Simulation mySimulation = null;
   private MSP430 myCpu = null;
@@ -276,7 +277,7 @@ public abstract class MspMote implements Mote {
     }
 
     long maxSimTimeCycles = NR_CYCLES_PER_MSEC*(simTime+1);
-    if (maxSimTimeCycles <= cycleCounter) {
+    if (maxSimTimeCycles <= cycleCounter - cycleDrift) {
       return false;
     }
 
diff --git a/tools/cooja/apps/mspsim/src/se/sics/cooja/mspmote/interfaces/MspClock.java b/tools/cooja/apps/mspsim/src/se/sics/cooja/mspmote/interfaces/MspClock.java
index 348394a30..c2add1eb5 100644
--- a/tools/cooja/apps/mspsim/src/se/sics/cooja/mspmote/interfaces/MspClock.java
+++ b/tools/cooja/apps/mspsim/src/se/sics/cooja/mspmote/interfaces/MspClock.java
@@ -26,7 +26,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: MspClock.java,v 1.1 2008/02/07 14:54:16 fros4943 Exp $
+ * $Id: MspClock.java,v 1.2 2008/09/17 17:39:37 nifi Exp $
  */
 
 package se.sics.cooja.mspmote.interfaces;
@@ -61,11 +61,12 @@ public class MspClock extends Clock {
   }
 
   public int getTime() {
-    return (int) (cpu.cycles / MspMote.NR_CYCLES_PER_MSEC);
+    int time = (int) ((cpu.cycles + myMote.cycleDrift) / MspMote.NR_CYCLES_PER_MSEC);
+    return time > 0 ? time : 0;
   }
 
   public void setDrift(int drift) {
-    myMote.cycleCounter = -MspMote.NR_CYCLES_PER_MSEC * drift;
+    myMote.cycleDrift = MspMote.NR_CYCLES_PER_MSEC * drift;
   }
 
   public void doActionsBeforeTick() {