diff --git a/TESTS/mbed_hal_fpga_ci_test_shield/pwm/main.cpp b/TESTS/mbed_hal_fpga_ci_test_shield/pwm/main.cpp
index 5220221a10..7124fce635 100644
--- a/TESTS/mbed_hal_fpga_ci_test_shield/pwm/main.cpp
+++ b/TESTS/mbed_hal_fpga_ci_test_shield/pwm/main.cpp
@@ -127,6 +127,7 @@ void fpga_pwm_period_fill_test(PinName pin, uint32_t period_ms, uint32_t fill_pr
             break;
     }
 
+    // wait_us is safe to call as this test disable the IRQs on execution.
     wait_us(PERIOD_US(period_ms));
 
     tester.io_metrics_start();
diff --git a/targets/TARGET_ARM_SSG/TARGET_CM3DS_MPS2/device/drivers/smsc9220_eth_drv.c b/targets/TARGET_ARM_SSG/TARGET_CM3DS_MPS2/device/drivers/smsc9220_eth_drv.c
index 5c929a740c..3ef7501f18 100644
--- a/targets/TARGET_ARM_SSG/TARGET_CM3DS_MPS2/device/drivers/smsc9220_eth_drv.c
+++ b/targets/TARGET_ARM_SSG/TARGET_CM3DS_MPS2/device/drivers/smsc9220_eth_drv.c
@@ -859,7 +859,7 @@ uint32_t smsc9220_get_tx_data_fifo_size(
 
 enum smsc9220_error_t smsc9220_init(
         const struct smsc9220_eth_dev_t* dev,
-        void(* wait_ms_function)(int))
+        void(* wait_ms_function)(uint32_t))
 {
     uint32_t phyreset = 0;
     enum smsc9220_error_t error = SMSC9220_ERROR_NONE;
diff --git a/targets/TARGET_ARM_SSG/TARGET_CM3DS_MPS2/device/drivers/smsc9220_eth_drv.h b/targets/TARGET_ARM_SSG/TARGET_CM3DS_MPS2/device/drivers/smsc9220_eth_drv.h
index 3c60f45bbb..296bb59745 100644
--- a/targets/TARGET_ARM_SSG/TARGET_CM3DS_MPS2/device/drivers/smsc9220_eth_drv.h
+++ b/targets/TARGET_ARM_SSG/TARGET_CM3DS_MPS2/device/drivers/smsc9220_eth_drv.h
@@ -38,7 +38,7 @@ struct smsc9220_eth_dev_cfg_t {
 struct smsc9220_eth_dev_data_t {
     uint32_t state;       /*!< Indicates if the SMSC9220 driver
                                is initialized and enabled */
-    void (*wait_ms) (int);/*!< function pointer to system's millisec delay
+    void (*wait_ms) (uint32_t);/*!< function pointer to system's millisec delay
                                function, will be used for delays */
     uint32_t ongoing_packet_length;/*!< size in bytes of the packet
                                             is being sent */
@@ -195,7 +195,7 @@ enum smsc9220_fifo_level_irq_pos_t{
  * \return error code /ref smsc9220_error_t
  */
 enum smsc9220_error_t smsc9220_init(const struct smsc9220_eth_dev_t* dev,
-                               void(* wait_ms_function)(int));
+                               void(* wait_ms_function)(uint32_t));
 
 /**
  * \brief Reads the MAC register.
diff --git a/targets/TARGET_RENESAS/TARGET_RZ_A1XX/TARGET_GR_LYCHEE/trng_api_esp32.cpp b/targets/TARGET_RENESAS/TARGET_RZ_A1XX/TARGET_GR_LYCHEE/trng_api_esp32.cpp
index d2f1b17c8f..d99a1e1cbd 100644
--- a/targets/TARGET_RENESAS/TARGET_RZ_A1XX/TARGET_GR_LYCHEE/trng_api_esp32.cpp
+++ b/targets/TARGET_RENESAS/TARGET_RZ_A1XX/TARGET_GR_LYCHEE/trng_api_esp32.cpp
@@ -17,6 +17,7 @@
 #if DEVICE_TRNG
 #include "drivers/I2C.h"
 #include "platform/mbed_wait_api.h"
+#include "rtos/ThisThread.h"
 
 #define ESP32_I2C_ADDR    (0x28<<1)
 #define RETRY_CNT_MAX     (20)
@@ -47,7 +48,9 @@ extern "C" void trng_init_esp32(void)
         GPIOPM3  &= ~0x4000;         /* Output mode */
 
         GPIOP3   |=  0x4000;         /* Outputs hi level */
-        ThisThread::sleep_for(5);
+
+        rtos::ThisThread::sleep_for(5);
+
         GPIOP5   |=  0x0008;         /* Outputs hi level */
     }
 }
@@ -84,7 +87,7 @@ extern "C" int trng_get_bytes_esp32(uint8_t *output, size_t length, size_t *outp
         }
         if (ret != 0) {
             retry_cnt++;
-            ThisThread::sleep_for(100);
+            rtos::ThisThread::sleep_for(100);
         }
     }
     if (retry_cnt >= RETRY_CNT_MAX) {
diff --git a/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F413xH/TARGET_MTS_DRAGONFLY_F413RH/ONBOARD_TELIT_HE910.cpp b/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F413xH/TARGET_MTS_DRAGONFLY_F413RH/ONBOARD_TELIT_HE910.cpp
index d5307b6382..cc6d08bb06 100644
--- a/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F413xH/TARGET_MTS_DRAGONFLY_F413RH/ONBOARD_TELIT_HE910.cpp
+++ b/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F413xH/TARGET_MTS_DRAGONFLY_F413RH/ONBOARD_TELIT_HE910.cpp
@@ -49,7 +49,7 @@ nsapi_error_t ONBOARD_TELIT_HE910::soft_power_on()
     /* keep the power line low for 200 milisecond */
     press_power_button(200);
     /* give modem a little time to respond */
-    ThisThread::sleep_for(100);
+    rtos::ThisThread::sleep_for(100);
     // From Telit_xE910 Global form factor App note: It is mandatory to avoid sending data to the serial ports during the first 200ms of the module start-up.
     rtos::ThisThread::sleep_for(200);
     return NSAPI_ERROR_OK;
@@ -64,7 +64,7 @@ nsapi_error_t ONBOARD_TELIT_HE910::soft_power_off()
      * If 3G_ON_OFF pin is kept low for more than a second, a controlled disconnect and shutdown takes
      * place, Due to the network disconnect, shut-off can take up to 30 seconds. However, we wait for 10
      * seconds only   */
-    ThisThread::sleep_for(10 * 1000);
+    rtos::ThisThread::sleep_for(10 * 1000);
     return NSAPI_ERROR_OK;
 }
 
@@ -74,7 +74,7 @@ void ONBOARD_TELIT_HE910::press_power_button(int time_ms)
 
     gpio_init_out_ex(&gpio, MDMPWRON, 1);
     gpio_write(&gpio, 0);
-    ThisThread::sleep_for(time_ms);
+    rtos::ThisThread::sleep_for(time_ms);
     gpio_write(&gpio, 1);
 }