diff --git a/src/machine/machine_stm32_adc_f1.go b/src/machine/machine_stm32_adc_f1.go
index fb0cee66..e2c82f62 100644
--- a/src/machine/machine_stm32_adc_f1.go
+++ b/src/machine/machine_stm32_adc_f1.go
@@ -75,7 +75,7 @@ func (a ADC) Get() uint16 {
 	stm32.ADC1.SR.ClearBits(stm32.ADC_SR_EOC)
 
 	// clear rank
-	stm32.ADC1.SMPR1.ClearBits(ch)
+	stm32.ADC1.SQR3.ClearBits(ch)
 
 	return result
 }
diff --git a/src/machine/machine_stm32_adc_f4.go b/src/machine/machine_stm32_adc_f4.go
index 4f0b8d11..3a163ffd 100644
--- a/src/machine/machine_stm32_adc_f4.go
+++ b/src/machine/machine_stm32_adc_f4.go
@@ -70,7 +70,7 @@ func (a ADC) Get() uint16 {
 	stm32.ADC1.SR.ClearBits(stm32.ADC_SR_EOC)
 
 	// clear rank
-	stm32.ADC1.SMPR1.ClearBits(ch)
+	stm32.ADC1.SQR3.ClearBits(ch)
 
 	return result
 }