diff --git a/src/stm32/stm32h7_adc.c b/src/stm32/stm32h7_adc.c
index ddec7d88..b9e14916 100644
--- a/src/stm32/stm32h7_adc.c
+++ b/src/stm32/stm32h7_adc.c
@@ -237,11 +237,10 @@ gpio_adc_setup(uint32_t pin)
             ;
 
         // Enable ADC
-        // "Clear the ADRDY bit in the ADC_ISR register by writing ‘1’"
-        adc->ISR |= ADC_ISR_ADRDY;
+        adc->ISR = ADC_ISR_ADRDY;
         adc->ISR; // Dummy read to make sure write is flushed
         adc->CR |= ADC_CR_ADEN;
-        while(!(adc->ISR & ADC_ISR_ADRDY))
+        while (!(adc->ISR & ADC_ISR_ADRDY))
            ;
 
         // Set ADC clock cycles sample time for every channel