diff --git a/src/stm32/stm32h7_adc.c b/src/stm32/stm32h7_adc.c
index 792a3335..2733b24f 100644
--- a/src/stm32/stm32h7_adc.c
+++ b/src/stm32/stm32h7_adc.c
@@ -114,7 +114,9 @@ gpio_adc_setup(uint32_t pin)
     ADC_TypeDef *adc;
     if (chan >= 40){
         adc = ADC3;
-        enable_pclock(ADC3_BASE);
+        if (!is_enabled_pclock(ADC3_BASE)) {
+            enable_pclock(ADC3_BASE);
+        }
         MODIFY_REG(ADC3_COMMON->CCR, ADC_CCR_CKMODE_Msk,
             0b11 << ADC_CCR_CKMODE_Pos);
     } else if (chan >= 20){