diff --git a/rtos/TARGET_CORTEX/rtx5/Include/cmsis_os2.h b/rtos/TARGET_CORTEX/rtx5/Include/cmsis_os2.h
index 73fee84d3c..2cbb293041 100644
--- a/rtos/TARGET_CORTEX/rtx5/Include/cmsis_os2.h
+++ b/rtos/TARGET_CORTEX/rtx5/Include/cmsis_os2.h
@@ -363,6 +363,7 @@ uint32_t osKernelGetSysTimerFreq (void);
 /// \param[in]     attr          thread attributes; NULL: default values.
 /// \return thread ID for reference by other functions or NULL in case of error.
 osThreadId_t osThreadNew (osThreadFunc_t func, void *argument, const osThreadAttr_t *attr);
+osThreadId_t osThreadContextNew (osThreadFunc_t func, void *argument, const osThreadAttr_t *attr, void *context);
  
 /// Get name of a thread.
 /// \param[in]     thread_id     thread ID obtained by \ref osThreadNew or \ref osThreadGetId.
diff --git a/rtos/TARGET_CORTEX/rtx5/RTX/Include/rtx_os.h b/rtos/TARGET_CORTEX/rtx5/RTX/Include/rtx_os.h
index cbb3f6a3dd..0c2df7e6a3 100644
--- a/rtos/TARGET_CORTEX/rtx5/RTX/Include/rtx_os.h
+++ b/rtos/TARGET_CORTEX/rtx5/RTX/Include/rtx_os.h
@@ -127,6 +127,7 @@ typedef struct osRtxThread_s {
   uint32_t                         sp;  ///< Current Stack Pointer
   uint32_t                thread_addr;  ///< Thread entry address
   uint32_t                  tz_memory;  ///< TrustZone Memory Identifier
+  void                       *context;  ///< Context for OsEventObserver objects
 } osRtxThread_t;
  
  
diff --git a/rtos/TARGET_CORTEX/rtx5/RTX/Source/rtx_kernel.c b/rtos/TARGET_CORTEX/rtx5/RTX/Source/rtx_kernel.c
index fad31603bf..d9edfd1426 100644
--- a/rtos/TARGET_CORTEX/rtx5/RTX/Source/rtx_kernel.c
+++ b/rtos/TARGET_CORTEX/rtx5/RTX/Source/rtx_kernel.c
@@ -245,7 +245,7 @@ osStatus_t svcRtxKernelStart (void) {
 
   // Create Idle Thread
   if (osRtxInfo.thread.idle == NULL) {
-    osRtxInfo.thread.idle = svcRtxThreadNew(osRtxIdleThread, NULL, osRtxConfig.idle_thread_attr);
+    osRtxInfo.thread.idle = svcRtxThreadNew(osRtxIdleThread, NULL, osRtxConfig.idle_thread_attr, NULL);
     if (osRtxInfo.thread.idle == NULL) {
       EvrRtxKernelError(osError);
       return osError;
@@ -255,7 +255,7 @@ osStatus_t svcRtxKernelStart (void) {
   // Create Timer Thread
   if (osRtxConfig.timer_mq_mcnt != 0U) {
     if (osRtxInfo.timer.thread == NULL) {
-      osRtxInfo.timer.thread = svcRtxThreadNew(osRtxTimerThread, NULL, osRtxConfig.timer_thread_attr);
+      osRtxInfo.timer.thread = svcRtxThreadNew(osRtxTimerThread, NULL, osRtxConfig.timer_thread_attr, NULL);
       if (osRtxInfo.timer.thread == NULL) {
         EvrRtxKernelError(osError);
         return osError;
diff --git a/rtos/TARGET_CORTEX/rtx5/RTX/Source/rtx_lib.h b/rtos/TARGET_CORTEX/rtx5/RTX/Source/rtx_lib.h
index 17bfc00641..e5863f1b22 100644
--- a/rtos/TARGET_CORTEX/rtx5/RTX/Source/rtx_lib.h
+++ b/rtos/TARGET_CORTEX/rtx5/RTX/Source/rtx_lib.h
@@ -131,7 +131,7 @@ extern uint32_t         svcRtxKernelGetSysTimerCount (void);
 extern uint32_t         svcRtxKernelGetSysTimerFreq  (void);
 
 // Thread Service Calls
-extern osThreadId_t     svcRtxThreadNew          (osThreadFunc_t func, void *argument, const osThreadAttr_t *attr);
+extern osThreadId_t     svcRtxThreadNew          (osThreadFunc_t func, void *argument, const osThreadAttr_t *attr, void *context);
 extern const char *     svcRtxThreadGetName      (osThreadId_t thread_id);
 extern osThreadId_t     svcRtxThreadGetId        (void);
 extern osThreadState_t  svcRtxThreadGetState     (osThreadId_t thread_id);
diff --git a/rtos/TARGET_CORTEX/rtx5/RTX/Source/rtx_thread.c b/rtos/TARGET_CORTEX/rtx5/RTX/Source/rtx_thread.c
index 26e4c38c16..bec6712794 100644
--- a/rtos/TARGET_CORTEX/rtx5/RTX/Source/rtx_thread.c
+++ b/rtos/TARGET_CORTEX/rtx5/RTX/Source/rtx_thread.c
@@ -542,7 +542,7 @@ void osRtxThreadPostProcess (os_thread_t *thread) {
 //  ==== Service Calls ====
 
 //  Service Calls definitions
-SVC0_3M(ThreadNew,           osThreadId_t,    osThreadFunc_t, void *, const osThreadAttr_t *)
+SVC0_4M(ThreadNew,           osThreadId_t,    osThreadFunc_t, void *, const osThreadAttr_t *, void *)
 SVC0_1 (ThreadGetName,       const char *,    osThreadId_t)
 SVC0_0 (ThreadGetId,         osThreadId_t)
 SVC0_1 (ThreadGetState,      osThreadState_t, osThreadId_t)
@@ -565,8 +565,8 @@ SVC0_0 (ThreadFlagsGet,      uint32_t)
 SVC0_3 (ThreadFlagsWait,     uint32_t,        uint32_t, uint32_t, uint32_t)
 
 /// Create a thread and add it to Active Threads.
-/// \note API identical to osThreadNew
-osThreadId_t svcRtxThreadNew (osThreadFunc_t func, void *argument, const osThreadAttr_t *attr) {
+/// \note API identical to osThreadContextNew
+osThreadId_t svcRtxThreadNew (osThreadFunc_t func, void *argument, const osThreadAttr_t *attr, void *context) {
   os_thread_t  *thread;
   uint32_t      attr_bits;
   void         *stack_mem;
@@ -1498,12 +1498,16 @@ uint32_t isrRtxThreadFlagsSet (osThreadId_t thread_id, uint32_t flags) {
 
 /// Create a thread and add it to Active Threads.
 osThreadId_t osThreadNew (osThreadFunc_t func, void *argument, const osThreadAttr_t *attr) {
+  return osThreadContextNew(func, argument, attr, NULL);
+}
+
+osThreadId_t osThreadContextNew (osThreadFunc_t func, void *argument, const osThreadAttr_t *attr, void *context) {
   EvrRtxThreadNew(func, argument, attr);
   if (IS_IRQ_MODE() || IS_IRQ_MASKED()) {
     EvrRtxThreadError(NULL, osErrorISR);
     return NULL;
   }
-  return __svcThreadNew(func, argument, attr);
+  return __svcThreadNew(func, argument, attr, context);
 }
 
 /// Get name of a thread.