diff --git a/src/clock.c b/src/clock.c
index 4fa73da472e73e55e43c065599cc71ecd55f2f8a..5fcd1d4ae49415ae2a5870cfc1c7c5001dd4f8bf 100644
--- a/src/clock.c
+++ b/src/clock.c
@@ -107,15 +107,20 @@ void rt_tick_increase(void)
  *
  * @return the calculated tick
  */
-int rt_tick_from_millisecond(rt_int32_t ms)
+rt_tick_t rt_tick_from_millisecond(rt_int32_t ms)
 {
-    int tick;
+    rt_tick_t tick;
 
     if (ms < 0)
+    {    
         tick = RT_WAITING_FOREVER;
+    }
     else
-        tick = (RT_TICK_PER_SECOND * ms + 999) / 1000;
-
+    {
+        tick = RT_TICK_PER_SECOND * (ms / 1000);
+        tick += (RT_TICK_PER_SECOND * (ms%1000) + 999) / 1000;
+    }
+    
     /* return the calculated tick */
     return tick;
 }