diff --git a/hardware/common/dmm/fs9721.c b/hardware/common/dmm/fs9721.c
index 6a55c716..a914add8 100644
--- a/hardware/common/dmm/fs9721.c
+++ b/hardware/common/dmm/fs9721.c
@@ -368,3 +368,16 @@ SR_PRIV int sr_fs9721_parse(const uint8_t *buf, float *floatval,
 
 	return SR_OK;
 }
+
+SR_PRIV void sr_fs9721_details_c2c1_00_temp_celsius(struct sr_datafeed_analog *analog, void *info)
+{
+	struct fs9721_info *info_local;
+
+	info_local = (struct fs9721_info *)info;
+
+	/* User-defined FS9721_LP3 flag 'c2c1_00' means temperature (C). */
+	if (info_local->is_c2c1_00) {
+		analog->mq = SR_MQ_TEMPERATURE;
+		analog->unit = SR_UNIT_CELSIUS;
+	}
+}
diff --git a/hardware/serial-dmm/api.c b/hardware/serial-dmm/api.c
index 89ea0dc8..c0eeba04 100644
--- a/hardware/serial-dmm/api.c
+++ b/hardware/serial-dmm/api.c
@@ -155,7 +155,7 @@ SR_PRIV struct dmm_info dmms[] = {
 		"Voltcraft", "VC-840 (UT-D02 cable)", "2400/8n1/rts=0/dtr=1",
 		2400, FS9721_PACKET_SIZE, NULL,
 		sr_fs9721_packet_valid, sr_fs9721_parse,
-		NULL,
+		sr_fs9721_details_c2c1_00_temp_celsius,
 		&voltcraft_vc840_ser_driver_info,
 		receive_data_VOLTCRAFT_VC840_SER,
 	},
diff --git a/hardware/serial-dmm/protocol.c b/hardware/serial-dmm/protocol.c
index 04d0dc69..6e697586 100644
--- a/hardware/serial-dmm/protocol.c
+++ b/hardware/serial-dmm/protocol.c
@@ -46,7 +46,7 @@ SR_PRIV void dmm_details_tp4000zc(struct sr_datafeed_analog *analog, void *info)
 
 	info_local = (struct fs9721_info *)info;
 
-	/* User-defined FS9721_LP3 flag 'c2c1_10' means temperature. */
+	/* User-defined FS9721_LP3 flag 'c2c1_10' means temperature (C). */
 	if (info_local->is_c2c1_10) {
 		analog->mq = SR_MQ_TEMPERATURE;
 		analog->unit = SR_UNIT_CELSIUS;
@@ -59,7 +59,7 @@ SR_PRIV void dmm_details_va18b(struct sr_datafeed_analog *analog, void *info)
 
 	info_local = (struct fs9721_info *)info;
 
-	/* User-defined FS9721_LP3 flag 'c2c1_01' means temperature. */
+	/* User-defined FS9721_LP3 flag 'c2c1_01' means temperature (C). */
 	if (info_local->is_c2c1_01) {
 		analog->mq = SR_MQ_TEMPERATURE;
 		analog->unit = SR_UNIT_CELSIUS;
diff --git a/hardware/uni-t-dmm/api.c b/hardware/uni-t-dmm/api.c
index e2a15d98..1e8a621c 100644
--- a/hardware/uni-t-dmm/api.c
+++ b/hardware/uni-t-dmm/api.c
@@ -68,7 +68,7 @@ SR_PRIV struct dmm_info udmms[] = {
 		"Voltcraft", "VC-840", 2400,
 		FS9721_PACKET_SIZE, NULL,
 		sr_fs9721_packet_valid, sr_fs9721_parse,
-		NULL,
+		sr_fs9721_details_c2c1_00_temp_celsius,
 		&voltcraft_vc840_driver_info, receive_data_VOLTCRAFT_VC840,
 	},
 };
diff --git a/libsigrok-internal.h b/libsigrok-internal.h
index 6e1cac2d..4396cc15 100644
--- a/libsigrok-internal.h
+++ b/libsigrok-internal.h
@@ -228,6 +228,7 @@ struct fs9721_info {
 SR_PRIV gboolean sr_fs9721_packet_valid(const uint8_t *buf);
 SR_PRIV int sr_fs9721_parse(const uint8_t *buf, float *floatval,
 			    struct sr_datafeed_analog *analog, void *info);
+SR_PRIV void sr_fs9721_details_c2c1_00_temp_celsius(struct sr_datafeed_analog *analog, void *info);
 
 /*--- hardware/common/dmm/metex14.c -----------------------------------------*/