diff --git a/core/net/mac/tsch/tsch-private.h b/core/net/mac/tsch/tsch-private.h
index 4a26abff3..44c928ae7 100644
--- a/core/net/mac/tsch/tsch-private.h
+++ b/core/net/mac/tsch/tsch-private.h
@@ -48,6 +48,10 @@
 #include "net/linkaddr.h"
 #include "net/mac/tsch/tsch-asn.h"
 #include "net/mac/tsch/tsch-conf.h"
+#if CONTIKI_TARGET_COOJA || CONTIKI_TARGET_COOJA_IP64
+#include "lib/simEnvChange.h"
+#include "sys/cooja_mt.h"
+#endif /* CONTIKI_TARGET_COOJA || CONTIKI_TARGET_COOJA_IP64 */
 
 /************ Types ***********/
 
@@ -109,7 +113,14 @@ void tsch_disassociate(void);
 #define TSCH_CLOCK_TO_SLOTS(c, timeslot_length) (TSCH_CLOCK_TO_TICKS(c) / timeslot_length)
 
 /* Wait for a condition with timeout t0+offset. */
+#if CONTIKI_TARGET_COOJA || CONTIKI_TARGET_COOJA_IP64
+#define BUSYWAIT_UNTIL_ABS(cond, t0, offset) \
+  while(!(cond) && RTIMER_CLOCK_LT(RTIMER_NOW(), (t0) + (offset))) { \
+    simProcessRunValue = 1; \
+    cooja_mt_yield(); \
+  };
+#else
 #define BUSYWAIT_UNTIL_ABS(cond, t0, offset) \
   while(!(cond) && RTIMER_CLOCK_LT(RTIMER_NOW(), (t0) + (offset))) ;
-
+#endif /* CONTIKI_TARGET_COOJA || CONTIKI_TARGET_COOJA_IP64 */
 #endif /* __TSCH_PRIVATE_H__ */
diff --git a/core/net/mac/tsch/tsch-slot-operation.c b/core/net/mac/tsch/tsch-slot-operation.c
index 62a7942f4..90e0fcad0 100644
--- a/core/net/mac/tsch/tsch-slot-operation.c
+++ b/core/net/mac/tsch/tsch-slot-operation.c
@@ -54,6 +54,10 @@
 #include "net/mac/tsch/tsch-packet.h"
 #include "net/mac/tsch/tsch-security.h"
 #include "net/mac/tsch/tsch-adaptive-timesync.h"
+#if CONTIKI_TARGET_COOJA || CONTIKI_TARGET_COOJA_IP64
+#include "lib/simEnvChange.h"
+#include "sys/cooja_mt.h"
+#endif /* CONTIKI_TARGET_COOJA || CONTIKI_TARGET_COOJA_IP64 */
 
 #if TSCH_LOG_LEVEL >= 1
 #define DEBUG DEBUG_PRINT
@@ -104,7 +108,10 @@
 #if RTIMER_SECOND < (32 * 1024)
 #error "TSCH: RTIMER_SECOND < (32 * 1024)"
 #endif
-#if RTIMER_SECOND >= 200000
+#if CONTIKI_TARGET_COOJA || CONTIKI_TARGET_COOJA_IP64
+/* Use 0 usec guard time for Cooja Mote with a 1 MHz Rtimer*/
+#define RTIMER_GUARD 0u
+#elif RTIMER_SECOND >= 200000
 #define RTIMER_GUARD (RTIMER_SECOND / 100000)
 #else
 #define RTIMER_GUARD 2u
@@ -200,7 +207,12 @@ tsch_get_lock(void)
     if(tsch_in_slot_operation) {
       busy_wait = 1;
       busy_wait_time = RTIMER_NOW();
-      while(tsch_in_slot_operation);
+      while(tsch_in_slot_operation) {
+#if CONTIKI_TARGET_COOJA || CONTIKI_TARGET_COOJA_IP64
+        simProcessRunValue = 1;
+        cooja_mt_yield();
+#endif /* CONTIKI_TARGET_COOJA || CONTIKI_TARGET_COOJA_IP64 */
+      }
       busy_wait_time = RTIMER_NOW() - busy_wait_time;
     }
     if(!tsch_locked) {