diff --git a/arch/platform/cooja/rtimer-arch.h b/arch/platform/cooja/rtimer-arch.h
index 072333bc1..35bd892b4 100644
--- a/arch/platform/cooja/rtimer-arch.h
+++ b/arch/platform/cooja/rtimer-arch.h
@@ -35,6 +35,8 @@
 
 #include "contiki.h"
 #include "sys/clock.h"
+#include "lib/simEnvChange.h"
+#include "sys/cooja_mt.h"
 
 #define RTIMER_ARCH_SECOND UINT64_C(1000000)
 
@@ -47,4 +49,17 @@ int rtimer_arch_check(void);
 int rtimer_arch_pending(void);
 rtimer_clock_t rtimer_arch_next(void);
 
+/** \brief A platform-specific implementation that calls cooja_mt_yield()
+ * periodically. Without this, Cooja will get stuck in the busy-loop
+ * without ever updating the current rtimer time. */
+#define RTIMER_BUSYWAIT_UNTIL_ABS(cond, t0, max_time) \
+  ({                                                                \
+    bool c;                                                         \
+    while(!(c = cond) && RTIMER_CLOCK_LT(RTIMER_NOW(), (t0) + (max_time))) { \
+      simProcessRunValue = 1;                                       \
+      cooja_mt_yield();                                             \
+    }                                                               \
+    c;                                                              \
+  })
+
 #endif /* RTIMER_ARCH_H_ */
diff --git a/os/sys/rtimer.h b/os/sys/rtimer.h
index 260f08950..783e1569b 100644
--- a/os/sys/rtimer.h
+++ b/os/sys/rtimer.h
@@ -189,14 +189,14 @@ void rtimer_arch_schedule(rtimer_clock_t t);
 #endif /* RTIMER_CONF_GUARD_TIME */
 
 /** \brief Busy-wait until a condition. Start time is t0, max wait time is max_time */
+#ifndef RTIMER_BUSYWAIT_UNTIL_ABS
 #define RTIMER_BUSYWAIT_UNTIL_ABS(cond, t0, max_time) \
   ({                                                                \
     bool c;                                                         \
-    while(!(c = cond) && RTIMER_CLOCK_LT(RTIMER_NOW(), (t0) + (max_time))) { \
-      watchdog_periodic();                                          \
-    }                                                               \
+    while(!(c = cond) && RTIMER_CLOCK_LT(RTIMER_NOW(), (t0) + (max_time))); \
     c;                                                              \
   })
+#endif /* RTIMER_BUSYWAIT_UNTIL_ABS */
 
 /** \brief Busy-wait until a condition for at most max_time */
 #define RTIMER_BUSYWAIT_UNTIL(cond, max_time)       \