diff --git a/ports/atmel-samd/common-hal/analogio/AnalogIn.c b/ports/atmel-samd/common-hal/analogio/AnalogIn.c
index 4140324a1c..e6db95b358 100644
--- a/ports/atmel-samd/common-hal/analogio/AnalogIn.c
+++ b/ports/atmel-samd/common-hal/analogio/AnalogIn.c
@@ -123,8 +123,8 @@ uint16_t common_hal_analogio_analogin_get_value(analogio_analogin_obj_t *self) {
     adc_sync_read_channel(&adc, self->channel, ((uint8_t *)&value), 2);
 
     adc_sync_deinit(&adc);
-    // Shift the value to be 16 bit.
-    return value << 4;
+    // Stretch 12-bit ADC reading to 16-bit range
+    return (value << 4) | (value >> 8);
 }
 
 float common_hal_analogio_analogin_get_reference_voltage(analogio_analogin_obj_t *self) {