diff --git a/CMSIS/RTOS2/RTX/Include/rtx_evr.h b/CMSIS/RTOS2/RTX/Include/rtx_evr.h
index 1dec30a79f..6d59289da0 100644
--- a/CMSIS/RTOS2/RTX/Include/rtx_evr.h
+++ b/CMSIS/RTOS2/RTX/Include/rtx_evr.h
@@ -872,9 +872,9 @@ extern void EvrRtxDelayUntil (uint32_t ticks);
   \param[in]  ticks         \ref CMSIS_RTOS_TimeOutValue "time ticks" value.
 */
 #if (!defined(EVR_RTX_DISABLE) && (OS_EVR_WAIT != 0) && !defined(EVR_RTX_DELAY_STARTED_DISABLE))
-extern void EvrRtxDelayStarted (uint32_t ticks);
+extern void EvrRtxDelayStarted (uint32_t ticks, osThreadId_t thread_id);
 #else
-#define EvrRtxDelayStarted(ticks)
+#define EvrRtxDelayStarted(ticks, thread_id)
 #endif
 
 /**
@@ -882,9 +882,9 @@ extern void EvrRtxDelayStarted (uint32_t ticks);
   \param[in]  ticks         \ref CMSIS_RTOS_TimeOutValue "time ticks" value.
 */
 #if (!defined(EVR_RTX_DISABLE) && (OS_EVR_WAIT != 0) && !defined(EVR_RTX_DELAY_UNTIL_STARTED_DISABLE))
-extern void EvrRtxDelayUntilStarted (uint32_t ticks);
+extern void EvrRtxDelayUntilStarted (uint32_t ticks, osThreadId_t thread_id);
 #else
-#define EvrRtxDelayUntilStarted(ticks)
+#define EvrRtxDelayUntilStarted(ticks, thread_id)
 #endif
 
 /**
diff --git a/CMSIS/RTOS2/RTX/RTX5.scvd b/CMSIS/RTOS2/RTX/RTX5.scvd
index 47659b1745..3957ed8a0d 100644
--- a/CMSIS/RTOS2/RTX/RTX5.scvd
+++ b/CMSIS/RTOS2/RTX/RTX5.scvd
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <component_viewer schemaVersion="1.2.0" xmlns:xs="http://www.w3.org/2001/XMLSchema-instance" xs:noNamespaceSchemaLocation="Component_Viewer.xsd">
-  <component name="CMSIS:RTOS2:Keil RTX5" shortname="RTX5" version="5.5.2"/>    <!-- name and version of the component -->
+  <component name="CMSIS:RTOS2:Keil RTX5" shortname="RTX5" version="5.5.3"/>    <!-- name and version of the component -->
 
   <typedefs>
     <!-- Attributes structure for thread -->
@@ -1468,8 +1468,8 @@
     <event id="0xF300 + 0x00" level="Error"  property="DelayError"         value="status=%E[val1, rtx_t:status]" info="osDelay/osDelayUntil error occurred."/>
     <event id="0xF300 + 0x01" level="API"    property="Delay"              value="ticks=%d[val1]" info="osDelay function was called."/>
     <event id="0xF300 + 0x02" level="API"    property="DelayUntil"         value="ticks=%d[val1]" info="osDelayUntil function was called."/>
-    <event id="0xF300 + 0x03" level="Op"     property="DelayStarted"       value="ticks=%d[val1]" info="osDelay started."/>
-    <event id="0xF300 + 0x04" level="Op"     property="DelayUntilStarted"  value="ticks=%d[val1]" info="osDelayUntil started."/>
+    <event id="0xF300 + 0x03" level="Op"     property="DelayStarted"       value="ticks=%d[val1], thread_id=%x[val2]" info="osDelay started."/>
+    <event id="0xF300 + 0x04" level="Op"     property="DelayUntilStarted"  value="ticks=%d[val1], thread_id=%x[val2]" info="osDelayUntil started."/>
     <event id="0xF300 + 0x05" level="Op"     property="DelayCompleted"     value="thread_id=%x[val1]" info="osDelay/osDelayUntil completed."/>
 
     <event id="0xF600 + 0x00" level="Error"  property="TimerError"     value="timer_id=%x[val1], status=%E[val2, rtx_t:status]" info="Timer error occurred."/>
diff --git a/CMSIS/RTOS2/RTX/Source/rtx_delay.c b/CMSIS/RTOS2/RTX/Source/rtx_delay.c
index 9d0cf414bf..3768b8b091 100644
--- a/CMSIS/RTOS2/RTX/Source/rtx_delay.c
+++ b/CMSIS/RTOS2/RTX/Source/rtx_delay.c
@@ -31,10 +31,14 @@
 /// Wait for Timeout (Time Delay).
 /// \note API identical to osDelay
 static osStatus_t svcRtxDelay (uint32_t ticks) {
+  os_thread_t *thread;
 
   if (ticks != 0U) {
+    // Get running thread
+    thread = osRtxThreadGetRunning();
+  	
     if (osRtxThreadWaitEnter(osRtxThreadWaitingDelay, ticks)) {
-      EvrRtxDelayStarted(ticks);
+      EvrRtxDelayStarted(ticks, thread);
     } else {
       EvrRtxDelayCompleted(osRtxThreadGetRunning());
     }
@@ -46,6 +50,7 @@ static osStatus_t svcRtxDelay (uint32_t ticks) {
 /// Wait until specified time.
 /// \note API identical to osDelayUntil
 static osStatus_t svcRtxDelayUntil (uint32_t ticks) {
+  os_thread_t *thread;
 
   ticks -= osRtxInfo.kernel.tick;
   if ((ticks == 0U) || (ticks > 0x7FFFFFFFU)) {
@@ -54,8 +59,11 @@ static osStatus_t svcRtxDelayUntil (uint32_t ticks) {
     return osErrorParameter;
   }
 
+  // Get running thread
+  thread = osRtxThreadGetRunning();
+
   if (osRtxThreadWaitEnter(osRtxThreadWaitingDelay, ticks)) {
-    EvrRtxDelayUntilStarted(ticks);
+    EvrRtxDelayUntilStarted(ticks, thread);
   } else {
     EvrRtxDelayCompleted(osRtxThreadGetRunning());
   }
diff --git a/CMSIS/RTOS2/RTX/Source/rtx_evr.c b/CMSIS/RTOS2/RTX/Source/rtx_evr.c
index 042d254270..9204e5ff81 100644
--- a/CMSIS/RTOS2/RTX/Source/rtx_evr.c
+++ b/CMSIS/RTOS2/RTX/Source/rtx_evr.c
@@ -1011,9 +1011,9 @@ __WEAK void EvrRtxDelayUntil (uint32_t ticks) {
 #endif
 
 #if (!defined(EVR_RTX_DISABLE) && (OS_EVR_WAIT != 0) && !defined(EVR_RTX_DELAY_STARTED_DISABLE))
-__WEAK void EvrRtxDelayStarted (uint32_t ticks) {
+__WEAK void EvrRtxDelayStarted (uint32_t ticks, osThreadId_t thread_id) {
 #if defined(RTE_Compiler_EventRecorder)
-  (void)EventRecord2(EvtRtxDelayStarted, ticks, 0U);
+  (void)EventRecord2(EvtRtxDelayStarted, ticks, thread_id);
 #else
   (void)ticks;
 #endif
@@ -1021,9 +1021,9 @@ __WEAK void EvrRtxDelayStarted (uint32_t ticks) {
 #endif
 
 #if (!defined(EVR_RTX_DISABLE) && (OS_EVR_WAIT != 0) && !defined(EVR_RTX_DELAY_UNTIL_STARTED_DISABLE))
-__WEAK void EvrRtxDelayUntilStarted (uint32_t ticks) {
+__WEAK void EvrRtxDelayUntilStarted (uint32_t ticks, osThreadId_t thread_id) {
 #if defined(RTE_Compiler_EventRecorder)
-  (void)EventRecord2(EvtRtxDelayUntilStarted, ticks, 0U);
+  (void)EventRecord2(EvtRtxDelayUntilStarted, ticks, thread_id);
 #else
   (void)ticks;
 #endif