diff --git a/events/source/equeue_mbed.cpp b/events/source/equeue_mbed.cpp
index 2380df4523..9d9deaee2e 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/source/mbed_os_timer.h"
+#include "platform/internal/mbed_os_timer.h"
 
 void equeue_tick_init()
 {
diff --git a/platform/source/SysTimer.h b/platform/include/platform/internal/SysTimer.h
similarity index 100%
rename from platform/source/SysTimer.h
rename to platform/include/platform/internal/SysTimer.h
diff --git a/platform/source/mbed_error_hist.h b/platform/include/platform/internal/mbed_error_hist.h
similarity index 100%
rename from platform/source/mbed_error_hist.h
rename to platform/include/platform/internal/mbed_error_hist.h
diff --git a/platform/source/mbed_os_timer.h b/platform/include/platform/internal/mbed_os_timer.h
similarity index 99%
rename from platform/source/mbed_os_timer.h
rename to platform/include/platform/internal/mbed_os_timer.h
index 7d17f9eabd..29d78c17c7 100644
--- a/platform/source/mbed_os_timer.h
+++ b/platform/include/platform/internal/mbed_os_timer.h
@@ -18,7 +18,7 @@
 #define MBED_MBED_SLEEP_TIMER_H
 
 #include <chrono>
-#include "platform/source/SysTimer.h"
+#include "platform/internal/SysTimer.h"
 
 #if MBED_CONF_RTOS_PRESENT
 extern "C" {
diff --git a/platform/source/SysTimer.cpp b/platform/source/SysTimer.cpp
index 8c387d5a67..2345e68bdd 100644
--- a/platform/source/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/source/SysTimer.h"
+#include "platform/internal/SysTimer.h"
 extern "C" {
 #if MBED_CONF_RTOS_PRESENT
 #include "rtx_lib.h"
diff --git a/platform/source/mbed_error.c b/platform/source/mbed_error.c
index e596b4986c..17ec1cf2be 100644
--- a/platform/source/mbed_error.c
+++ b/platform/source/mbed_error.c
@@ -22,11 +22,11 @@
 #include "platform/mbed_atomic.h"
 #include "platform/mbed_critical.h"
 #include "platform/mbed_error.h"
-#include "platform/source/mbed_error_hist.h"
 #include "platform/mbed_interface.h"
 #include "platform/mbed_power_mgmt.h"
 #include "platform/mbed_stats.h"
 #include "platform/internal/mbed_fault_handler.h"
+#include "platform/internal/mbed_error_hist.h"
 #include "drivers/MbedCRC.h"
 #include "mbed_rtx.h"
 #ifdef MBED_CONF_RTOS_PRESENT
diff --git a/platform/source/mbed_error_hist.c b/platform/source/mbed_error_hist.c
index 4a686885f7..4b8f0ba454 100644
--- a/platform/source/mbed_error_hist.c
+++ b/platform/source/mbed_error_hist.c
@@ -21,7 +21,7 @@
 #include "platform/mbed_critical.h"
 
 #if MBED_CONF_PLATFORM_ERROR_HIST_ENABLED
-#include "platform/source/mbed_error_hist.h"
+#include "platform/internal/mbed_error_hist.h"
 
 static mbed_error_ctx mbed_error_ctx_log[MBED_CONF_PLATFORM_ERROR_HIST_SIZE] = {0};
 static int error_log_count = -1;
diff --git a/platform/source/mbed_os_timer.cpp b/platform/source/mbed_os_timer.cpp
index 17126eea9b..9fcf1b1793 100644
--- a/platform/source/mbed_os_timer.cpp
+++ b/platform/source/mbed_os_timer.cpp
@@ -16,9 +16,9 @@
  */
 
 #include "platform/mbed_power_mgmt.h"
-#include "platform/source/mbed_os_timer.h"
 #include "platform/CriticalSectionLock.h"
-#include "platform/source/SysTimer.h"
+#include "platform/internal/SysTimer.h"
+#include "platform/internal/mbed_os_timer.h"
 #include "us_ticker_api.h"
 #include "lp_ticker_api.h"
 #include "mbed_critical.h"
diff --git a/platform/source/mbed_thread.cpp b/platform/source/mbed_thread.cpp
index 08d2cb26bf..8adce55bd5 100644
--- a/platform/source/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/source/mbed_os_timer.h"
+#include "platform/internal/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/include/rtos/Kernel.h b/rtos/include/rtos/Kernel.h
index c653b163f0..b9e7c57a5c 100644
--- a/rtos/include/rtos/Kernel.h
+++ b/rtos/include/rtos/Kernel.h
@@ -28,7 +28,7 @@
 #include "rtos/mbed_rtos_types.h"
 #include "platform/mbed_toolchain.h"
 #if !MBED_CONF_RTOS_PRESENT
-#include "platform/source/mbed_os_timer.h"
+#include "platform/internal/mbed_os_timer.h"
 #endif
 
 
diff --git a/rtos/source/EventFlags.cpp b/rtos/source/EventFlags.cpp
index bd235cd81f..508f3167cb 100644
--- a/rtos/source/EventFlags.cpp
+++ b/rtos/source/EventFlags.cpp
@@ -22,7 +22,7 @@
  */
 #include "rtos/EventFlags.h"
 #include "rtos/ThisThread.h"
-#include "mbed_os_timer.h"
+#include "platform/internal/mbed_os_timer.h"
 #include <string.h>
 #include "platform/mbed_error.h"
 #include "platform/mbed_assert.h"
diff --git a/rtos/source/Kernel.cpp b/rtos/source/Kernel.cpp
index 5f99e49119..de0491abee 100644
--- a/rtos/source/Kernel.cpp
+++ b/rtos/source/Kernel.cpp
@@ -25,7 +25,7 @@
 #include "rtos_idle.h"
 #include "rtos_handlers.h"
 #include "platform/mbed_critical.h"
-#include "platform/source/mbed_os_timer.h"
+#include "platform/internal/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 204bfa7171..c36afde557 100644
--- a/rtos/source/Semaphore.cpp
+++ b/rtos/source/Semaphore.cpp
@@ -25,7 +25,7 @@
 #include "platform/mbed_assert.h"
 #include "platform/mbed_critical.h"
 #include "platform/mbed_error.h"
-#include "platform/source/mbed_os_timer.h"
+#include "platform/internal/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 1fdf070bde..5fe187ebd2 100644
--- a/rtos/source/TARGET_CORTEX/mbed_rtx_idle.cpp
+++ b/rtos/source/TARGET_CORTEX/mbed_rtx_idle.cpp
@@ -24,7 +24,7 @@
 #include "rtos/source/rtos_idle.h"
 #include "rtos/Kernel.h"
 #include "platform/mbed_power_mgmt.h"
-#include "platform/source/mbed_os_timer.h"
+#include "platform/internal/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 fe532da889..5494dcc5ff 100644
--- a/rtos/source/ThisThread.cpp
+++ b/rtos/source/ThisThread.cpp
@@ -29,7 +29,7 @@
 #include "platform/CriticalSectionLock.h"
 #include "platform/mbed_assert.h"
 #include "platform/mbed_critical.h"
-#include "platform/source/mbed_os_timer.h"
+#include "platform/internal/mbed_os_timer.h"
 
 using std::milli;
 using std::chrono::duration;
diff --git a/rtos/tests/TESTS/mbedmicro-rtos-mbed/systimer/main.cpp b/rtos/tests/TESTS/mbedmicro-rtos-mbed/systimer/main.cpp
index 6999f018d7..067848b487 100644
--- a/rtos/tests/TESTS/mbedmicro-rtos-mbed/systimer/main.cpp
+++ b/rtos/tests/TESTS/mbedmicro-rtos-mbed/systimer/main.cpp
@@ -21,7 +21,7 @@
 #include "utest.h"
 #include "ticker_api.h"
 
-#include "platform/source/SysTimer.h"
+#include "platform/internal/SysTimer.h"
 
 using namespace std::chrono;