diff --git a/include/libsigrok/libsigrok.h b/include/libsigrok/libsigrok.h
index 3daf616d..31ee5dce 100644
--- a/include/libsigrok/libsigrok.h
+++ b/include/libsigrok/libsigrok.h
@@ -1015,6 +1015,9 @@ enum sr_configkey {
 	/** The device supports setting a probe factor. */
 	SR_CONF_PROBE_FACTOR,
 
+	/** Number of powerline cycles for ADC integration time. */
+	SR_CONF_ADC_POWERLINE_CYCLES,
+
 	/* Update sr_key_info_config[] (hwdriver.c) upon changes! */
 
 	/*--- Acquisition modes, sample limiting ----------------------------*/
diff --git a/src/hwdriver.c b/src/hwdriver.c
index 81a86a79..b31242ad 100644
--- a/src/hwdriver.c
+++ b/src/hwdriver.c
@@ -189,6 +189,8 @@ static struct sr_key_info sr_key_info_config[] = {
 		"Data source", NULL},
 	{SR_CONF_PROBE_FACTOR, SR_T_UINT64, "probe_factor",
 		"Probe factor", NULL},
+	{SR_CONF_ADC_POWERLINE_CYCLES, SR_T_FLOAT, "nplc",
+		"Number of ADC powerline cycles", NULL},
 
 	/* Acquisition modes, sample limiting */
 	{SR_CONF_LIMIT_MSEC, SR_T_UINT64, "limit_time",