diff --git a/TESTS/mbedmicro-rtos-mbed/systimer/main.cpp b/TESTS/mbedmicro-rtos-mbed/systimer/main.cpp
index 44492f1ec5d..13b60ac99d8 100644
--- a/TESTS/mbedmicro-rtos-mbed/systimer/main.cpp
+++ b/TESTS/mbedmicro-rtos-mbed/systimer/main.cpp
@@ -23,7 +23,7 @@
 extern "C" {
 #include "rtx_lib.h"
 }
-#include "platform/SysTimer.h"
+#include "platform/source/SysTimer.h"
 
 #define TEST_TICKS 42
 #define TEST_TICK_US (TEST_TICKS * 1000)
diff --git a/events/source/equeue_mbed.cpp b/events/source/equeue_mbed.cpp
index 394e12efbbf..f875f56f2a3 100644
--- a/events/source/equeue_mbed.cpp
+++ b/events/source/equeue_mbed.cpp
@@ -38,7 +38,7 @@ using namespace mbed;
 #if MBED_CONF_RTOS_API_PRESENT
 
 #include "rtos/Kernel.h"
-#include "platform/mbed_os_timer.h"
+#include "platform/source/mbed_os_timer.h"
 
 void equeue_tick_init()
 {
diff --git a/platform/mbed_thread.h b/platform/mbed_thread.h
index 6968ebd62fd..8b9fff1ea21 100644
--- a/platform/mbed_thread.h
+++ b/platform/mbed_thread.h
@@ -22,6 +22,12 @@
 extern "C" {
 #endif
 
+/**
+ * \defgroup mbed_thread Mbed Thread
+ * \ingroup platform-public-api
+ * @{
+ */
+
 /** Generic thread functions.
  *
  * These are C versions of functions provided in C++ via rtos::Thread and rtos::ThisThread
@@ -59,6 +65,8 @@ void thread_sleep_for(uint32_t millisec);
 */
 void thread_sleep_until(uint64_t millisec);
 
+/** @}*/
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/platform/SysTimer.cpp b/platform/source/SysTimer.cpp
similarity index 99%
rename from platform/SysTimer.cpp
rename to platform/source/SysTimer.cpp
index a79a4b8bd6d..8186c114f82 100644
--- a/platform/SysTimer.cpp
+++ b/platform/source/SysTimer.cpp
@@ -22,7 +22,7 @@
 #include "mbed_assert.h"
 #include "platform/mbed_power_mgmt.h"
 #include "platform/CriticalSectionLock.h"
-#include "platform/SysTimer.h"
+#include "platform/source/SysTimer.h"
 extern "C" {
 #if MBED_CONF_RTOS_PRESENT
 #include "rtx_lib.h"
diff --git a/platform/SysTimer.h b/platform/source/SysTimer.h
similarity index 98%
rename from platform/SysTimer.h
rename to platform/source/SysTimer.h
index f6e3b2ad402..3098a8e6142 100644
--- a/platform/SysTimer.h
+++ b/platform/source/SysTimer.h
@@ -32,12 +32,8 @@ namespace mbed {
 namespace internal {
 
 /**
- * @cond MBED_INTERNAL
- *
- * @addtogroup mbed
- * @{
- *
- * @defgroup mbed_SysTimer SysTimer class
+ * \defgroup mbed_SysTimer SysTimer class
+ * \ingroup platform-internal-api
  * @{
  */
 
@@ -239,11 +235,7 @@ class SysTimer: private mbed::TimerEvent, private mbed::NonCopyable<SysTimer<US_
     bool _deep_sleep_locked;
 };
 
-/**
- * @}
- * @}
- * @endcond
- */
+/** @} */
 
 }
 }
diff --git a/platform/mbed_os_timer.cpp b/platform/source/mbed_os_timer.cpp
similarity index 99%
rename from platform/mbed_os_timer.cpp
rename to platform/source/mbed_os_timer.cpp
index 30322491deb..8f7525465f4 100644
--- a/platform/mbed_os_timer.cpp
+++ b/platform/source/mbed_os_timer.cpp
@@ -16,9 +16,9 @@
  */
 
 #include "platform/mbed_power_mgmt.h"
-#include "platform/mbed_os_timer.h"
+#include "platform/source/mbed_os_timer.h"
 #include "platform/CriticalSectionLock.h"
-#include "platform/SysTimer.h"
+#include "platform/source/SysTimer.h"
 #include "us_ticker_api.h"
 #include "lp_ticker_api.h"
 #include "mbed_critical.h"
diff --git a/platform/mbed_os_timer.h b/platform/source/mbed_os_timer.h
similarity index 98%
rename from platform/mbed_os_timer.h
rename to platform/source/mbed_os_timer.h
index 639dc3fdfd8..a765e911da5 100644
--- a/platform/mbed_os_timer.h
+++ b/platform/source/mbed_os_timer.h
@@ -17,7 +17,7 @@
 #ifndef MBED_MBED_SLEEP_TIMER_H
 #define MBED_MBED_SLEEP_TIMER_H
 
-#include "platform/SysTimer.h"
+#include "platform/source/SysTimer.h"
 
 #if MBED_CONF_RTOS_PRESENT
 extern "C" {
diff --git a/platform/mbed_thread.cpp b/platform/source/mbed_thread.cpp
similarity index 97%
rename from platform/mbed_thread.cpp
rename to platform/source/mbed_thread.cpp
index 0cdcae15496..f24f8e2c554 100644
--- a/platform/mbed_thread.cpp
+++ b/platform/source/mbed_thread.cpp
@@ -17,7 +17,7 @@
 
 #include "platform/mbed_thread.h"
 #include "platform/mbed_critical.h"
-#include "platform/mbed_os_timer.h"
+#include "platform/source/mbed_os_timer.h"
 
 /* If the RTOS is present, we call the RTOS API to do the work */
 /* If the RTOS is not present, the RTOS API calls us to do the work */
diff --git a/rtos/source/Kernel.cpp b/rtos/source/Kernel.cpp
index e5e34433000..c62a4b93aa1 100644
--- a/rtos/source/Kernel.cpp
+++ b/rtos/source/Kernel.cpp
@@ -24,7 +24,7 @@
 #include "rtos_idle.h"
 #include "rtos_handlers.h"
 #include "platform/mbed_critical.h"
-#include "platform/mbed_os_timer.h"
+#include "platform/source/mbed_os_timer.h"
 
 #if !MBED_CONF_RTOS_PRESENT
 /* If the RTOS is not present, we call mbed_thread.cpp to do the work */
diff --git a/rtos/source/Semaphore.cpp b/rtos/source/Semaphore.cpp
index 8ae83c9f698..86d5db6d979 100644
--- a/rtos/source/Semaphore.cpp
+++ b/rtos/source/Semaphore.cpp
@@ -24,7 +24,7 @@
 #include "platform/mbed_assert.h"
 #include "platform/mbed_critical.h"
 #include "platform/mbed_error.h"
-#include "platform/mbed_os_timer.h"
+#include "platform/source/mbed_os_timer.h"
 
 #include <string.h>
 
diff --git a/rtos/source/TARGET_CORTEX/mbed_rtx_idle.cpp b/rtos/source/TARGET_CORTEX/mbed_rtx_idle.cpp
index 27b6d5e4786..36e5d7c036d 100644
--- a/rtos/source/TARGET_CORTEX/mbed_rtx_idle.cpp
+++ b/rtos/source/TARGET_CORTEX/mbed_rtx_idle.cpp
@@ -22,7 +22,7 @@
 
 #include "rtos/source/rtos_idle.h"
 #include "platform/mbed_power_mgmt.h"
-#include "platform/mbed_os_timer.h"
+#include "platform/source/mbed_os_timer.h"
 #include "TimerEvent.h"
 #include "mbed_critical.h"
 #include "mbed_assert.h"
diff --git a/rtos/source/ThisThread.cpp b/rtos/source/ThisThread.cpp
index 0ee2d73f297..e02b4bbf0fb 100644
--- a/rtos/source/ThisThread.cpp
+++ b/rtos/source/ThisThread.cpp
@@ -28,7 +28,7 @@
 #include "platform/CriticalSectionLock.h"
 #include "platform/mbed_assert.h"
 #include "platform/mbed_critical.h"
-#include "platform/mbed_os_timer.h"
+#include "platform/source/mbed_os_timer.h"
 
 #if !MBED_CONF_RTOS_PRESENT
 /* If the RTOS is not present, we call mbed_thread.cpp to do the work */