diff --git a/drivers/adc/adc_nrfx_saadc.c b/drivers/adc/adc_nrfx_saadc.c
index 23ddbc2a5b0..052eab45b6c 100644
--- a/drivers/adc/adc_nrfx_saadc.c
+++ b/drivers/adc/adc_nrfx_saadc.c
@@ -133,6 +133,7 @@ static int adc_convert_acq_time(uint16_t acquisition_time, nrf_saadc_acqtime_t *
 	case ADC_ACQ_TIME(ADC_ACQ_TIME_MICROSECONDS, 20):
 		*p_tacq_val = NRF_SAADC_ACQTIME_20US;
 		break;
+	case ADC_ACQ_TIME_MAX:
 	case ADC_ACQ_TIME(ADC_ACQ_TIME_MICROSECONDS, 40):
 		*p_tacq_val = NRF_SAADC_ACQTIME_40US;
 		break;