diff --git a/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/TARGET_MCU_NRF51822/analogin_api.c b/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/TARGET_MCU_NRF51822/analogin_api.c
index 02384a90b2..ac349e0d36 100644
--- a/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/TARGET_MCU_NRF51822/analogin_api.c
+++ b/hal/targets/hal/TARGET_NORDIC/TARGET_NRF5/TARGET_MCU_NRF51822/analogin_api.c
@@ -58,7 +58,7 @@ void analogin_init(analogin_t *obj, PinName pin)
 
 uint16_t analogin_read_u16(analogin_t *obj)
 {
-    nrf_adc_value_t adc_value = 0xFFFF;
+    nrf_adc_value_t adc_value;
        
     nrf_drv_adc_channel_t adc_channel = NRF_DRV_ADC_DEFAULT_CHANNEL(obj->adc_pin);