diff --git a/testhal/RP/RP2040/RT-RP2040-PICO-ADC/main.c b/testhal/RP/RP2040/RT-RP2040-PICO-ADC/main.c
index 6f9f7e5f22..4da2e507fd 100644
--- a/testhal/RP/RP2040/RT-RP2040-PICO-ADC/main.c
+++ b/testhal/RP/RP2040/RT-RP2040-PICO-ADC/main.c
@@ -77,7 +77,6 @@ int main(void) {
    * Activates the UART0 SIO driver using the default configuration.
    */
   sioStart(&SIOD0, NULL);
-  sioStartOperation(&SIOD0, NULL);
 
   /*
    * Setting up GPIOs.
diff --git a/testhal/RP/RP2040/RT-RP2040-PICO-I2C-24AA01/main.c b/testhal/RP/RP2040/RT-RP2040-PICO-I2C-24AA01/main.c
index e45f909ea5..2f802b576b 100644
--- a/testhal/RP/RP2040/RT-RP2040-PICO-I2C-24AA01/main.c
+++ b/testhal/RP/RP2040/RT-RP2040-PICO-I2C-24AA01/main.c
@@ -61,7 +61,6 @@ int main(void) {
    * Activates the UART0 SIO driver using the default configuration.
    */
   sioStart(&SIOD0, NULL);
-  sioStartOperation(&SIOD0, NULL);
 
   /* LED GPIO */
   palSetLineMode(LED_GREEN_PIN, PAL_MODE_OUTPUT_PUSHPULL | PAL_RP_PAD_DRIVE12);
diff --git a/testhal/SAMD21A/EFL-MFS/main.c b/testhal/SAMD21A/EFL-MFS/main.c
index c388527b99..94fdeacee4 100644
--- a/testhal/SAMD21A/EFL-MFS/main.c
+++ b/testhal/SAMD21A/EFL-MFS/main.c
@@ -80,7 +80,6 @@ int main(void)
 
   /* Start SIO */
   sioStart(&SIOD3, &siocfg);
-  sioStartOperation(&SIOD3, NULL);
 
   /* Starting EFL driver.*/
   eflStart(&EFLD1, NULL);
diff --git a/testhal/SAMD21A/SIO/main.c b/testhal/SAMD21A/SIO/main.c
index 30f510ab2c..f3d3f765be 100644
--- a/testhal/SAMD21A/SIO/main.c
+++ b/testhal/SAMD21A/SIO/main.c
@@ -88,7 +88,6 @@ int main(void)
   palSetPadMode(GPIOA, 10, PAL_MODE_ALTERNATE(PAL_SAM_FUNC_D));
   palSetPadMode(GPIOA, 11, PAL_MODE_ALTERNATE(PAL_SAM_FUNC_D));
   sioStart(&SIOD3, &siocfg);
-  sioStartOperation(&SIOD3, NULL);
 
   /*
    * Shell manager initialization.