diff --git a/src/libsdr/sdr.c b/src/libsdr/sdr.c
index e7221cf..a316d95 100644
--- a/src/libsdr/sdr.c
+++ b/src/libsdr/sdr.c
@@ -374,7 +374,7 @@ void *sdr_open(const char __attribute__((__unused__)) *audiodev, double *tx_freq
 
 #ifdef HAVE_UHD
 	if (sdr_config->uhd) {
-		rc = uhd_open(sdr_config->channel, sdr_config->device_args, sdr_config->stream_args, sdr_config->tune_args, sdr_config->tx_antenna, sdr_config->rx_antenna, tx_center_frequency, rx_center_frequency, sdr_config->lo_offset, sdr_config->samplerate, sdr_config->tx_gain, sdr_config->rx_gain, sdr_config->bandwidth, sdr_config->uhd_tx_timestamps);
+		rc = uhd_open(sdr_config->channel, sdr_config->device_args, sdr_config->stream_args, sdr_config->tune_args, sdr_config->tx_antenna, sdr_config->rx_antenna, sdr_config->clock_source, tx_center_frequency, rx_center_frequency, sdr_config->lo_offset, sdr_config->samplerate, sdr_config->tx_gain, sdr_config->rx_gain, sdr_config->bandwidth, sdr_config->uhd_tx_timestamps);
 		if (rc)
 			goto error;
 	}
@@ -382,7 +382,7 @@ void *sdr_open(const char __attribute__((__unused__)) *audiodev, double *tx_freq
 
 #ifdef HAVE_SOAPY
 	if (sdr_config->soapy) {
-		rc = soapy_open(sdr_config->channel, sdr_config->device_args, sdr_config->stream_args, sdr_config->tune_args, sdr_config->tx_antenna, sdr_config->rx_antenna, tx_center_frequency, rx_center_frequency, sdr_config->lo_offset, sdr_config->samplerate, sdr_config->tx_gain, sdr_config->rx_gain, sdr_config->bandwidth);
+		rc = soapy_open(sdr_config->channel, sdr_config->device_args, sdr_config->stream_args, sdr_config->tune_args, sdr_config->tx_antenna, sdr_config->rx_antenna, sdr_config->clock_source, tx_center_frequency, rx_center_frequency, sdr_config->lo_offset, sdr_config->samplerate, sdr_config->tx_gain, sdr_config->rx_gain, sdr_config->bandwidth);
 		if (rc)
 			goto error;
 	}
diff --git a/src/libsdr/sdr_config.c b/src/libsdr/sdr_config.c
index dfbada7..0ff021d 100644
--- a/src/libsdr/sdr_config.c
+++ b/src/libsdr/sdr_config.c
@@ -76,6 +76,8 @@ void sdr_config_print_help(void)
 	printf("        SDR device's RX antenna name, use 'list' to get a list\n");
 	printf("    --sdr-tx-antenna <name>\n");
 	printf("        SDR device's TX antenna name, use 'list' to get a list\n");
+	printf("    --sdr-clock-source <name>\n");
+	printf("        SDR device's clock sourc name, use 'list' to get a list\n");
 	printf("    --sdr-rx-gain <gain>\n");
 	printf("        SDR device's RX gain in dB (default = %.1f)\n", sdr_config->rx_gain);
 	printf("    --sdr-tx-gain <gain>\n");
@@ -111,17 +113,18 @@ void sdr_config_print_hotkeys(void)
 #define	OPT_SDR_TUNE_ARGS	1505
 #define	OPT_SDR_RX_ANTENNA	1506
 #define	OPT_SDR_TX_ANTENNA	1507
-#define	OPT_SDR_RX_GAIN		1508
-#define	OPT_SDR_TX_GAIN		1509
-#define	OPT_SDR_SAMPLERATE	1510
-#define	OPT_SDR_LO_OFFSET	1511
-#define	OPT_SDR_BANDWIDTH	1512
-#define	OPT_WRITE_IQ_RX_WAVE	1513
-#define	OPT_WRITE_IQ_TX_WAVE	1514
-#define	OPT_READ_IQ_RX_WAVE	1515
-#define	OPT_READ_IQ_TX_WAVE	1516
-#define	OPT_SDR_SWAP_LINKS	1517
-#define OPT_SDR_UHD_TX_TS	1518
+#define	OPT_SDR_CLOCK_SOURCE	1508
+#define	OPT_SDR_RX_GAIN		1509
+#define	OPT_SDR_TX_GAIN		1510
+#define	OPT_SDR_SAMPLERATE	1511
+#define	OPT_SDR_LO_OFFSET	1512
+#define	OPT_SDR_BANDWIDTH	1513
+#define	OPT_WRITE_IQ_RX_WAVE	1514
+#define	OPT_WRITE_IQ_TX_WAVE	1515
+#define	OPT_READ_IQ_RX_WAVE	1516
+#define	OPT_READ_IQ_TX_WAVE	1517
+#define	OPT_SDR_SWAP_LINKS	1518
+#define	OPT_SDR_UHD_TX_TS	1519
 
 void sdr_config_add_options(void)
 {
@@ -136,6 +139,7 @@ void sdr_config_add_options(void)
 	option_add(OPT_SDR_BANDWIDTH, "sdr-bandwidth", 1);
 	option_add(OPT_SDR_RX_ANTENNA, "sdr-rx-antenna", 1);
 	option_add(OPT_SDR_TX_ANTENNA, "sdr-tx-antenna", 1);
+	option_add(OPT_SDR_CLOCK_SOURCE, "sdr-clock-source", 1);
 	option_add(OPT_SDR_RX_GAIN, "sdr-rx-gain", 1);
 	option_add(OPT_SDR_TX_GAIN, "sdr-tx-gain", 1);
 	option_add(OPT_WRITE_IQ_RX_WAVE, "write-iq-rx-wave", 1);
@@ -194,6 +198,9 @@ int sdr_config_handle_options(int short_option, int argi, char **argv)
 	case OPT_SDR_TX_ANTENNA:
 		sdr_config->tx_antenna = strdup(argv[argi]);
 		break;
+	case OPT_SDR_CLOCK_SOURCE:
+		sdr_config->clock_source = strdup(argv[argi]);
+		break;
 	case OPT_SDR_RX_GAIN:
 		sdr_config->rx_gain = atof(argv[argi]);
 		break;
diff --git a/src/libsdr/sdr_config.h b/src/libsdr/sdr_config.h
index 1feb323..37f3643 100644
--- a/src/libsdr/sdr_config.h
+++ b/src/libsdr/sdr_config.h
@@ -13,6 +13,7 @@ typedef struct sdr_config {
 			rx_gain;
 	const char	*tx_antenna,		/* list/override antennas */
 			*rx_antenna;
+	const char	*clock_source;		/* list/override clock source */
 	const char	*write_iq_tx_wave;	/* wave recording and playback */
 	const char	*write_iq_rx_wave;
 	const char	*read_iq_tx_wave;
diff --git a/src/libsdr/soapy.c b/src/libsdr/soapy.c
index 9c33dfb..0919060 100644
--- a/src/libsdr/soapy.c
+++ b/src/libsdr/soapy.c
@@ -62,10 +62,10 @@ static int parse_args(SoapySDRKwargs *args, const char *_args_string)
 	return 0;
 }
 
-int soapy_open(size_t channel, const char *_device_args, const char *_stream_args, const char *_tune_args, const char *tx_antenna, const char *rx_antenna, double tx_frequency, double rx_frequency, double lo_offset, double rate, double tx_gain, double rx_gain, double bandwidth)
+int soapy_open(size_t channel, const char *_device_args, const char *_stream_args, const char *_tune_args, const char *tx_antenna, const char *rx_antenna, const char *clock_source, double tx_frequency, double rx_frequency, double lo_offset, double rate, double tx_gain, double rx_gain, double bandwidth)
 {
 	double got_frequency, got_rate, got_gain, got_bandwidth;
-	const char *got_antenna;
+	const char *got_antenna, *got_clock;
 	size_t num_channels;
 	SoapySDRKwargs device_args;
 	SoapySDRKwargs stream_args;
@@ -103,6 +103,42 @@ int soapy_open(size_t channel, const char *_device_args, const char *_stream_arg
 		return -EIO;
 	}
 
+	/* clock source */
+	if (clock_source && clock_source[0]) {
+		if (!strcasecmp(clock_source, "list")) {
+			char **clocks;
+			size_t clocks_length;
+			int i;
+			clocks = SoapySDRDevice_listClockSources(sdr, &clocks_length);
+			if (!clocks) {
+				PDEBUG(DSOAPY, DEBUG_ERROR, "Failed to request list of clock sources!\n");
+				soapy_close();
+				return -EIO;
+			}
+			if (clocks_length) {
+				for (i = 0; i < (int)clocks_length; i++)
+					PDEBUG(DSOAPY, DEBUG_NOTICE, "Clock source: '%s'\n", clocks[i]);
+				got_clock = SoapySDRDevice_getClockSource(sdr);
+				PDEBUG(DSOAPY, DEBUG_NOTICE, "Default clock source: '%s'\n", got_clock);
+			} else
+				PDEBUG(DSOAPY, DEBUG_NOTICE, "There are no clock sources configurable for this device.\n");
+			soapy_close();
+			return 1;
+		}
+
+		if (SoapySDRDevice_setClockSource(sdr, clock_source) != 0) {
+			PDEBUG(DSOAPY, DEBUG_ERROR, "Failed to set clock source to '%s'\n", clock_source);
+			soapy_close();
+			return -EIO;
+		}
+		got_clock = SoapySDRDevice_getClockSource(sdr);
+		if (!!strcasecmp(clock_source, got_clock)) {
+			PDEBUG(DSOAPY, DEBUG_NOTICE, "Given clock source '%s' was accepted, but driver claims to use '%s'\n", clock_source, got_clock);
+			soapy_close();
+			return -EINVAL;
+		}
+	}
+
 	if (rx_frequency) {
 		/* get number of channels and check if requested channel is in range */
 		num_channels = SoapySDRDevice_getNumChannels(sdr, SOAPY_SDR_RX);
diff --git a/src/libsdr/soapy.h b/src/libsdr/soapy.h
index 755d0ca..c411b5b 100644
--- a/src/libsdr/soapy.h
+++ b/src/libsdr/soapy.h
@@ -1,5 +1,5 @@
 
-int soapy_open(size_t channel, const char *_device_args, const char *_stream_args, const char *_tune_args, const char *tx_antenna, const char *rx_antenna, double tx_frequency, double rx_frequency, double lo_offset, double rate, double tx_gain, double rx_gain, double bandwidth);
+int soapy_open(size_t channel, const char *_device_args, const char *_stream_args, const char *_tune_args, const char *tx_antenna, const char *rx_antenna, const char *clock_source, double tx_frequency, double rx_frequency, double lo_offset, double rate, double tx_gain, double rx_gain, double bandwidth);
 int soapy_start(void);
 void soapy_close(void);
 int soapy_send(float *buff, int num);
diff --git a/src/libsdr/uhd.c b/src/libsdr/uhd.c
index 624146f..dc99125 100644
--- a/src/libsdr/uhd.c
+++ b/src/libsdr/uhd.c
@@ -49,11 +49,11 @@ static time_t			tx_time_secs = 0;
 static double			tx_time_fract_sec = 0.0;
 static int			tx_timestamps;
 
-int uhd_open(size_t channel, const char *_device_args, const char *_stream_args, const char *_tune_args, const char *tx_antenna, const char *rx_antenna, double tx_frequency, double rx_frequency, double lo_offset, double rate, double tx_gain, double rx_gain, double bandwidth, int _tx_timestamps)
+int uhd_open(size_t channel, const char *_device_args, const char *_stream_args, const char *_tune_args, const char *tx_antenna, const char *rx_antenna, const char *clock_source, double tx_frequency, double rx_frequency, double lo_offset, double rate, double tx_gain, double rx_gain, double bandwidth, int _tx_timestamps)
 {
 	uhd_error error;
 	double got_frequency, got_rate, got_gain, got_bandwidth;
-	char got_antenna[64];
+	char got_antenna[64], got_clock[64];
 
 	samplerate = rate;
 	tx_timestamps = _tx_timestamps;
@@ -71,6 +71,64 @@ int uhd_open(size_t channel, const char *_device_args, const char *_stream_args,
 		return -EIO;
 	}
 
+	/* clock source */
+	if (clock_source && clock_source[0]) {
+		if (!strcasecmp(clock_source, "list")) {
+			uhd_string_vector_handle clocks;
+			size_t clocks_length;
+			int i;
+			error = uhd_string_vector_make(&clocks);
+			if (error) {
+				clock_vector_error:
+				PDEBUG(DUHD, DEBUG_ERROR, "Failed to hande UHD vector, please fix!\n");
+				uhd_close();
+				return -EIO;
+			}
+			error = uhd_usrp_get_clock_sources(usrp, 0, &clocks);
+			if (error) {
+				PDEBUG(DUHD, DEBUG_ERROR, "Failed to request list of clock sources!\n");
+				uhd_close();
+				return -EIO;
+			}
+			error = uhd_string_vector_size(clocks, &clocks_length);
+			if (error)
+				goto clock_vector_error;
+			for (i = 0; i < (int)clocks_length; i++) {
+				error = uhd_string_vector_at(clocks, i, got_clock, sizeof(got_clock));
+				if (error)
+					goto clock_vector_error;
+				PDEBUG(DUHD, DEBUG_NOTICE, "Clock source: '%s'\n", got_clock);
+			}
+			uhd_string_vector_free(&clocks);
+			error = uhd_usrp_get_clock_source(usrp, 0, got_clock, sizeof(got_clock));
+			if (error) {
+				PDEBUG(DUHD, DEBUG_ERROR, "Failed to get clock source\n");
+				uhd_close();
+				return -EINVAL;
+			}
+			PDEBUG(DUHD, DEBUG_NOTICE, "Default clock source: '%s'\n", got_clock);
+			uhd_close();
+			return 1;
+		}
+		error = uhd_usrp_set_clock_source(usrp, clock_source, 0);
+		if (error) {
+			PDEBUG(DUHD, DEBUG_ERROR, "Failed to set clock source to '%s'\n", clock_source);
+			uhd_close();
+			return -EIO;
+		}
+		error = uhd_usrp_get_clock_source(usrp, 0, got_clock, sizeof(got_clock));
+		if (error) {
+			PDEBUG(DUHD, DEBUG_ERROR, "Failed to get clock source\n");
+			uhd_close();
+			return -EINVAL;
+		}
+		if (!!strcasecmp(clock_source, got_clock)) {
+			PDEBUG(DUHD, DEBUG_NOTICE, "Given clock source '%s' was accepted, but driver claims to use '%s'\n", clock_source, got_clock);
+			uhd_close();
+			return -EINVAL;
+		}
+	}
+
 	if (tx_frequency) {
 		/* antenna */
 		if (tx_antenna && tx_antenna[0]) {
diff --git a/src/libsdr/uhd.h b/src/libsdr/uhd.h
index 36ce1ba..ad80e57 100644
--- a/src/libsdr/uhd.h
+++ b/src/libsdr/uhd.h
@@ -1,5 +1,5 @@
 
-int uhd_open(size_t channel, const char *_device_args, const char *_stream_args, const char *_tune_args, const char *tx_antenna, const char *rx_antenna, double tx_frequency, double rx_frequency, double lo_offset, double rate, double tx_gain, double rx_gain, double bandwidth, int _tx_timestamps);
+int uhd_open(size_t channel, const char *_device_args, const char *_stream_args, const char *_tune_args, const char *tx_antenna, const char *rx_antenna, const char *clock_source, double tx_frequency, double rx_frequency, double lo_offset, double rate, double tx_gain, double rx_gain, double bandwidth, int _tx_timestamps);
 int uhd_start(void);
 void uhd_close(void);
 int uhd_send(float *buff, int num);