diff --git a/ports/stm32/irq.h b/ports/stm32/irq.h
index 78ba46ced..4b1251666 100644
--- a/ports/stm32/irq.h
+++ b/ports/stm32/irq.h
@@ -120,7 +120,7 @@ MP_DECLARE_CONST_FUN_OBJ_0(pyb_irq_stats_obj);
 
 #if __CORTEX_M == 0
 
-//#def  IRQ_PRI_SYSTICK         0
+#define IRQ_PRI_SYSTICK         0
 #define IRQ_PRI_UART            1
 #define IRQ_PRI_SDIO            1
 #define IRQ_PRI_DMA             1
@@ -136,7 +136,7 @@ MP_DECLARE_CONST_FUN_OBJ_0(pyb_irq_stats_obj);
 
 #else
 
-//#def  IRQ_PRI_SYSTICK         NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 0, 0)
+#define IRQ_PRI_SYSTICK         NVIC_EncodePriority(NVIC_PRIORITYGROUP_4, 0, 0)
 
 // The UARTs have no FIFOs, so if they don't get serviced quickly then characters
 // get dropped. The handling for each character only consumes about 0.5 usec
diff --git a/ports/stm32/powerctrlboot.c b/ports/stm32/powerctrlboot.c
index 766c52dfb..acc33f125 100644
--- a/ports/stm32/powerctrlboot.c
+++ b/ports/stm32/powerctrlboot.c
@@ -27,6 +27,13 @@
 #include "py/mphal.h"
 #include "powerctrl.h"
 
+static inline void powerctrl_config_systick(void) {
+    // Configure SYSTICK to run at 1kHz (1ms interval)
+    SysTick->CTRL |= SYSTICK_CLKSOURCE_HCLK;
+    SysTick_Config(HAL_RCC_GetHCLKFreq() / 1000);
+    NVIC_SetPriority(SysTick_IRQn, IRQ_PRI_SYSTICK);
+}
+
 #if defined(STM32F0)
 
 void SystemClock_Config(void) {
@@ -88,9 +95,7 @@ void SystemClock_Config(void) {
     }
 
     SystemCoreClockUpdate();
-
-    HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq() / 1000);
-    HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);
+    powerctrl_config_systick();
 }
 
 #elif defined(STM32L0)
@@ -122,9 +127,7 @@ void SystemClock_Config(void) {
     }
 
     SystemCoreClockUpdate();
-
-    HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq() / 1000);
-    HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);
+    powerctrl_config_systick();
 
     #if MICROPY_HW_ENABLE_RNG || MICROPY_HW_ENABLE_USB
     // Enable the 48MHz internal oscillator
@@ -189,9 +192,7 @@ void SystemClock_Config(void) {
     RCC->CCIPR = 2 << RCC_CCIPR_CLK48SEL_Pos;
 
     SystemCoreClockUpdate();
-
-    HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq() / 1000);
-    HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);
+    powerctrl_config_systick();
 }
 
 #endif