diff --git a/lib/stm32/f1/adc.c b/lib/stm32/f1/adc.c
index 71eb9269..148d71cc 100644
--- a/lib/stm32/f1/adc.c
+++ b/lib/stm32/f1/adc.c
@@ -354,7 +354,7 @@ void adc_enable_discontinuous_mode_regular(u32 adc, u8 length)
 {
     if ( (length-1) > 7 ) return;
 	ADC_CR1(adc) |= ADC_CR1_DISCEN;	
-    ADC_CR2(adc) |= ((length-1) << ADC_CR1_DISCNUM_SHIFT);
+    ADC_CR1(adc) |= ((length-1) << ADC_CR1_DISCNUM_SHIFT);
 }
 
 /*-----------------------------------------------------------------------------*/
diff --git a/lib/stm32/f4/adc.c b/lib/stm32/f4/adc.c
index aef49a44..00edcc35 100644
--- a/lib/stm32/f4/adc.c
+++ b/lib/stm32/f4/adc.c
@@ -168,7 +168,7 @@ void adc_enable_discontinuous_mode_regular(u32 adc, u8 length)
 {
     if ( (length-1) > 7 ) return;
 	ADC_CR1(adc) |= ADC_CR1_DISCEN;	
-    ADC_CR2(adc) |= ((length-1) << ADC_CR1_DISCNUM_SHIFT);
+    ADC_CR1(adc) |= ((length-1) << ADC_CR1_DISCNUM_SHIFT);
 }
 
 /*-----------------------------------------------------------------------------*/