diff --git a/ports/mimxrt10xx/common-hal/microcontroller/Processor.c b/ports/mimxrt10xx/common-hal/microcontroller/Processor.c
index 17ced78910..34400e3f41 100644
--- a/ports/mimxrt10xx/common-hal/microcontroller/Processor.c
+++ b/ports/mimxrt10xx/common-hal/microcontroller/Processor.c
@@ -52,15 +52,13 @@ float common_hal_mcu_processor_get_temperature(void) {
     return temp;
 }
 
-uint32_t common_hal_mcu_processor_set_frequency(mcu_processor_obj_t *self,
+void common_hal_mcu_processor_set_frequency(mcu_processor_obj_t *self,
     uint32_t frequency) {
     uint32_t freq = frequency / 1000000;
     if (freq != 24 && freq != 150 && freq != 396 && freq != 450 && freq != 528 && freq != 600 &&
         freq != 720 && freq != 816 && freq != 912 && freq != 960 && freq != 1008) {
         mp_raise_ValueError(translate("Frequency must be 24, 150, 396, 450, 528, 600, 720, 816, 912, 960 or 1008 Mhz"));
     }
-    SystemCoreClock = setarmclock(frequency);
-    return SystemCoreClock;
 }
 
 
diff --git a/ports/raspberrypi/common-hal/microcontroller/Processor.c b/ports/raspberrypi/common-hal/microcontroller/Processor.c
index 08e6495d26..66083a357d 100644
--- a/ports/raspberrypi/common-hal/microcontroller/Processor.c
+++ b/ports/raspberrypi/common-hal/microcontroller/Processor.c
@@ -61,14 +61,10 @@ uint32_t common_hal_mcu_processor_get_frequency(void) {
     return clock_get_hz(clk_sys);
 }
 
-uint32_t common_hal_mcu_processor_set_frequency(mcu_processor_obj_t *self,
-    uint32_t frequency) {
-    uint32_t freq = frequency / 1000;
-
-    if (!set_sys_clock_khz(freq, false)) {
-        mp_raise_ValueError(translate("Invalid frequency supplied"));
+void common_hal_mcu_processor_set_frequency(mcu_processor_obj_t *self, uint32_t frequency) {
+    if (!set_sys_clock_khz(frequency / 1000, false)) {
+        mp_arg_error_invalid(MP_QSTR_frequency);
     }
-    return clock_get_hz(clk_sys);
 }
 
 void common_hal_mcu_processor_get_uid(uint8_t raw_id[]) {
diff --git a/shared-bindings/microcontroller/Processor.c b/shared-bindings/microcontroller/Processor.c
index f5190d36ef..6ae0212a6a 100644
--- a/shared-bindings/microcontroller/Processor.c
+++ b/shared-bindings/microcontroller/Processor.c
@@ -67,8 +67,11 @@
 //|     frequency: int
 //|     """The CPU operating frequency in Hertz.
 //|
-//|     **Limitations:** Setting the ``frequency`` is possible on RP2040 boards and some i.MX boards.
-//|     On most boards, ``frequency`` is read-only.
+//|     **Limitations:** On most boards, ``frequency`` is read-only. Setting
+//|     the ``frequency`` is possible on RP2040 boards and some i.MX boards.
+//|
+//|     .. warning:: On RP2040 boards changing the frequency may cause issues
+//|        with other subsystems, such as USB, PWM, and PIO.
 //|     """
 
 #if CIRCUITPY_SETTABLE_PROCESSOR_FREQUENCY
diff --git a/shared-bindings/microcontroller/Processor.h b/shared-bindings/microcontroller/Processor.h
index 9a2f22b245..473f25cbc6 100644
--- a/shared-bindings/microcontroller/Processor.h
+++ b/shared-bindings/microcontroller/Processor.h
@@ -39,6 +39,6 @@ mcu_reset_reason_t common_hal_mcu_processor_get_reset_reason(void);
 float common_hal_mcu_processor_get_temperature(void);
 void common_hal_mcu_processor_get_uid(uint8_t raw_id[]);
 float common_hal_mcu_processor_get_voltage(void);
-uint32_t common_hal_mcu_processor_set_frequency(mcu_processor_obj_t *self, uint32_t frequency);
+void common_hal_mcu_processor_set_frequency(mcu_processor_obj_t *self, uint32_t frequency);
 
 #endif  // MICROPY_INCLUDED_SHARED_BINDINGS_MICROCONTROLLER_PROCESSOR_H