diff --git a/firmware/common/radio.c b/firmware/common/radio.c
index 36f65cad7..b947cd624 100644
--- a/firmware/common/radio.c
+++ b/firmware/common/radio.c
@@ -60,6 +60,7 @@ void radio_init(radio_t* const radio)
 	radio->config[RADIO_BANK_TX][RADIO_OPMODE] = TRANSCEIVER_MODE_TX;
 	radio->config[RADIO_BANK_IDLE][RADIO_BIAS_TEE] = false;
 	radio->regs_dirty = 0;
+	radio->regs_locked = 0;
 }
 
 static inline void mark_dirty(radio_t* const radio, radio_register_t reg)
@@ -67,6 +68,11 @@ static inline void mark_dirty(radio_t* const radio, radio_register_t reg)
 	radio->regs_dirty |= (1 << reg);
 }
 
+static inline bool check_locked(radio_t* const radio, radio_register_t reg)
+{
+	return radio->regs_locked & (1 << reg);
+}
+
 radio_error_t radio_reg_write(
 	radio_t* const radio,
 	const radio_register_bank_t bank,
@@ -77,6 +83,10 @@ radio_error_t radio_reg_write(
 		return RADIO_ERR_INVALID_REGISTER;
 	}
 
+	if (check_locked(radio, reg)) {
+		return RADIO_ERR_LOCKED_REGISTER;
+	}
+
 	switch (bank) {
 	case RADIO_BANK_REQUESTED:
 		mark_dirty(radio, reg);
@@ -107,6 +117,20 @@ uint64_t radio_reg_read(
 	return radio->config[bank][reg];
 }
 
+radio_error_t radio_reg_lock(
+	radio_t* const radio,
+	const radio_register_t reg,
+	const bool locked)
+{
+	if (reg > RADIO_NUM_REGS) {
+		return RADIO_ERR_INVALID_REGISTER;
+	}
+
+	radio->regs_locked = (radio->regs_locked & ~(1 << reg)) | (locked << reg);
+
+	return RADIO_OK;
+}
+
 static uint32_t radio_update_direction(radio_t* const radio, uint64_t* bank)
 {
 	const uint64_t requested = bank[RADIO_OPMODE];
diff --git a/firmware/common/radio.h b/firmware/common/radio.h
index 8e12471a4..caaa222d3 100644
--- a/firmware/common/radio.h
+++ b/firmware/common/radio.h
@@ -34,6 +34,7 @@ typedef enum {
 	RADIO_ERR_INVALID_PARAM = -2,
 	RADIO_ERR_INVALID_BANK = -3,
 	RADIO_ERR_INVALID_REGISTER = -4,
+	RADIO_ERR_LOCKED_REGISTER = -5,
 	RADIO_ERR_UNSUPPORTED_OPERATION = -10,
 	RADIO_ERR_UNIMPLEMENTED = -19,
 	RADIO_ERR_OTHER = -9999,
@@ -231,6 +232,7 @@ typedef struct {
 	radio_config_mode_t config_mode;
 	uint64_t config[RADIO_NUM_BANKS][RADIO_NUM_REGS];
 	volatile uint32_t regs_dirty;
+	uint32_t regs_locked;
 	update_fn update_cb;
 } radio_t;
 
@@ -254,6 +256,15 @@ uint64_t radio_reg_read(
 	const radio_register_bank_t bank,
 	const radio_register_t reg);
 
+/**
+ * Lock a register. Prevents any future calls to `radio_reg_write`
+ * from overwriting the current stored value of the register.
+ */
+radio_error_t radio_reg_lock(
+	radio_t* const radio,
+	const radio_register_t reg,
+	const bool locked);
+
 /**
  * Apply changes requested in RADIO_BANK_REQUESTED.
  * Return true if any changes were applied.
diff --git a/firmware/hackrf_usb/hackrf_usb.c b/firmware/hackrf_usb/hackrf_usb.c
index 813a94539..4cdfbd14e 100644
--- a/firmware/hackrf_usb/hackrf_usb.c
+++ b/firmware/hackrf_usb/hackrf_usb.c
@@ -182,6 +182,7 @@ static usb_request_handler_fn vendor_request_handler[] = {
 	usb_vendor_request_write_radio_reg,
 	usb_vendor_request_read_radio_reg,
 	usb_vendor_request_get_buffer_size,
+	usb_vendor_request_lock_radio_reg,
 };
 
 static const uint32_t vendor_request_handler_count =
diff --git a/firmware/hackrf_usb/usb_api_register.c b/firmware/hackrf_usb/usb_api_register.c
index 626c75089..a46a22404 100644
--- a/firmware/hackrf_usb/usb_api_register.c
+++ b/firmware/hackrf_usb/usb_api_register.c
@@ -416,3 +416,20 @@ usb_request_status_t usb_vendor_request_read_radio_reg(
 	}
 	return USB_REQUEST_STATUS_OK;
 }
+
+usb_request_status_t usb_vendor_request_lock_radio_reg(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage)
+{
+	if (stage == USB_TRANSFER_STAGE_SETUP) {
+		uint8_t reg = endpoint->setup.index;
+		bool locked = endpoint->setup.value != 0 ? true : false;
+		if (reg >= RADIO_NUM_REGS) {
+			return USB_REQUEST_STATUS_STALL;
+		}
+		radio_reg_lock(&radio, reg, locked);
+		usb_transfer_schedule_ack(endpoint->in);
+	}
+
+	return USB_REQUEST_STATUS_OK;
+}
diff --git a/firmware/hackrf_usb/usb_api_register.h b/firmware/hackrf_usb/usb_api_register.h
index a5a36550d..7e434c1a7 100644
--- a/firmware/hackrf_usb/usb_api_register.h
+++ b/firmware/hackrf_usb/usb_api_register.h
@@ -70,3 +70,6 @@ usb_request_status_t usb_vendor_request_write_radio_reg(
 usb_request_status_t usb_vendor_request_read_radio_reg(
 	usb_endpoint_t* const endpoint,
 	const usb_transfer_stage_t stage);
+usb_request_status_t usb_vendor_request_lock_radio_reg(
+	usb_endpoint_t* const endpoint,
+	const usb_transfer_stage_t stage);
diff --git a/firmware/hackrf_usb/usb_descriptor.c b/firmware/hackrf_usb/usb_descriptor.c
index dde22e6e3..726e126a0 100644
--- a/firmware/hackrf_usb/usb_descriptor.c
+++ b/firmware/hackrf_usb/usb_descriptor.c
@@ -28,7 +28,7 @@
 
 #define USB_VENDOR_ID (0x1D50)
 
-#define USB_API_VERSION (0x0113)
+#define USB_API_VERSION (0x0114)
 
 #define USB_WORD(x) (x & 0xFF), ((x >> 8) & 0xFF)
 
diff --git a/host/hackrf-tools/src/hackrf_debug.c b/host/hackrf-tools/src/hackrf_debug.c
index 5f8785b52..475130ebc 100644
--- a/host/hackrf-tools/src/hackrf_debug.c
+++ b/host/hackrf-tools/src/hackrf_debug.c
@@ -545,6 +545,30 @@ int radio_write_register(
 	return result;
 }
 
+int radio_lock_register(
+	hackrf_device* device,
+	const uint16_t register_number,
+	const bool register_locked)
+{
+	int result = HACKRF_SUCCESS;
+	result = hackrf_radio_lock_register(
+		device,
+		(uint8_t) register_number,
+		register_locked);
+
+	if (result == HACKRF_SUCCESS) {
+		printf("register [%2d] -> %s\n",
+		       register_number,
+		       register_locked ? "locked" : "unlocked");
+	} else {
+		printf("hackrf_radio_lock_register() failed: %s (%d)\n",
+		       hackrf_error_name(result),
+		       result);
+	}
+
+	return result;
+}
+
 int read_register(
 	hackrf_device* device,
 	uint8_t part,
@@ -621,6 +645,20 @@ int write_register(
 	return HACKRF_ERROR_INVALID_PARAM;
 }
 
+int lock_register(
+	hackrf_device* device,
+	uint8_t part,
+	const uint16_t register_number,
+	const bool register_locked)
+{
+	switch (part) {
+	case PART_RADIO:
+		return radio_lock_register(device, register_number, register_locked);
+	default:
+		return HACKRF_ERROR_INVALID_PARAM;
+	}
+}
+
 static const char* mode_name(uint32_t mode)
 {
 	const char* mode_names[] = {"IDLE", "WAIT", "RX", "TX_START", "TX_RUN"};
@@ -675,6 +713,7 @@ static void usage()
 	printf("\t-n, --register <n>: set register number for read/write operations\n");
 	printf("\t-r, --read: read register specified by last -n argument, or all registers\n");
 	printf("\t-w, --write <v>: write register specified by last -n argument with value <v>\n");
+	printf("\t-L, --lock <state>: lock register specified by last -n argument (0 for unlocked, 1 for locked)\n");
 	printf("\t-c, --config: print SI5351C multisynth configuration information\n");
 	printf("\t-d, --device <s>: specify a particular device by serial number\n");
 	printf("\t-m, --max283x: target MAX283x\n");
@@ -709,6 +748,7 @@ static struct option long_options[] = {
 	{"register", required_argument, 0, 'n'},
 	{"write", required_argument, 0, 'w'},
 	{"read", no_argument, 0, 'r'},
+	{"lock", required_argument, 0, 'L'},
 	{"device", required_argument, 0, 'd'},
 	{"help", no_argument, 0, 'h'},
 	{"max2837", no_argument, 0, 'm'},
@@ -740,10 +780,12 @@ int main(int argc, char** argv)
 	int bank = -1;
 	uint64_t register_number = REGISTER_INVALID;
 	uint64_t register_value;
+	uint64_t register_locked;
 	hackrf_device* device = NULL;
 	int option_index = 0;
 	bool read = false;
 	bool write = false;
+	bool lock = false;
 	bool dump_config = false;
 	bool dump_state = false;
 	uint8_t part = PART_NONE;
@@ -782,7 +824,7 @@ int main(int argc, char** argv)
 	while ((opt = getopt_long(
 			argc,
 			argv,
-			"b:n:rw:d:cmsfgi1:2:C:N:P:ST:R:h?u:l:ta:o",
+			"b:n:rw:l:d:cmsfgi1:2:C:N:P:ST:R:h?u:l:ta:o",
 			long_options,
 			&option_index)) != EOF) {
 		switch (opt) {
@@ -805,6 +847,11 @@ int main(int argc, char** argv)
 			read = true;
 			break;
 
+		case 'L':
+			lock = true;
+			result = parse_int(optarg, &register_locked);
+			break;
+
 		case 'c':
 			dump_config = true;
 			break;
@@ -931,8 +978,8 @@ int main(int argc, char** argv)
 		}
 	}
 
-	if (write && read) {
-		fprintf(stderr, "Read and write options are mutually exclusive.\n");
+	if ((write && read) || (lock && write) || (lock && read)) {
+		fprintf(stderr, "Read, write and lock options are mutually exclusive.\n");
 		usage();
 		return EXIT_FAILURE;
 	}
@@ -949,6 +996,10 @@ int main(int argc, char** argv)
 		return EXIT_FAILURE;
 	}
 
+	if (lock && part != PART_RADIO) {
+		fprintf(stderr, "Lock option is only valid for radio.\n");
+	}
+
 	if ((bank > -1) && (part != PART_RADIO)) {
 		fprintf(stderr, "Bank valid only for radio.\n");
 		usage();
@@ -959,11 +1010,11 @@ int main(int argc, char** argv)
 		bank = 0;
 	}
 
-	if (!(write || read || dump_config || dump_state || set_tx_limit ||
+	if (!(write || read || lock || dump_config || dump_state || set_tx_limit ||
 	      set_rx_limit || set_ui || set_leds || set_p1 || set_p2 || set_clkin ||
 	      set_narrowband || set_fpga_bitstream || read_selftest || test_rtc_osc ||
 	      read_adc)) {
-		fprintf(stderr, "Specify read, write, or config option.\n");
+		fprintf(stderr, "Specify read, write, lock, or config option.\n");
 		usage();
 		return EXIT_FAILURE;
 	}
@@ -1016,6 +1067,10 @@ int main(int argc, char** argv)
 		}
 	}
 
+	if (lock) {
+		result = lock_register(device, part, register_number, register_locked);
+	}
+
 	if (dump_config) {
 		si5351c_read_configuration(device);
 	}
diff --git a/host/libhackrf/src/hackrf.c b/host/libhackrf/src/hackrf.c
index 4018ac63d..eab5bfe73 100644
--- a/host/libhackrf/src/hackrf.c
+++ b/host/libhackrf/src/hackrf.c
@@ -121,6 +121,7 @@ typedef enum {
 	HACKRF_VENDOR_REQUEST_RADIO_WRITE_REG = 59,
 	HACKRF_VENDOR_REQUEST_RADIO_READ_REG = 60,
 	HACKRF_VENDOR_REQUEST_GET_BUFFER_SIZE = 61,
+	HACKRF_VENDOR_REQUEST_RADIO_LOCK_REG = 62,
 } hackrf_vendor_request;
 
 #define USB_CONFIG_STANDARD 0x1
@@ -3575,6 +3576,33 @@ int ADDCALL hackrf_radio_write_register(
 	}
 }
 
+int ADDCALL hackrf_radio_lock_register(
+	hackrf_device* device,
+	const uint8_t register_number,
+	const bool register_locked)
+{
+	USB_API_REQUIRED(device, 0x0114);
+	int result;
+
+	result = libusb_control_transfer(
+		device->usb_device,
+		LIBUSB_ENDPOINT_OUT | LIBUSB_REQUEST_TYPE_VENDOR |
+			LIBUSB_RECIPIENT_DEVICE,
+		HACKRF_VENDOR_REQUEST_RADIO_LOCK_REG,
+		register_locked,
+		register_number,
+		NULL,
+		0,
+		DEFAULT_REQUEST_TIMEOUT);
+
+	if (result != 0) {
+		last_libusb_error = result;
+		return HACKRF_ERROR_LIBUSB;
+	}
+
+	return HACKRF_SUCCESS;
+}
+
 #ifdef __cplusplus
 } // __cplusplus defined.
 #endif
diff --git a/host/libhackrf/src/hackrf.h b/host/libhackrf/src/hackrf.h
index eeca65e03..6cf71dd91 100644
--- a/host/libhackrf/src/hackrf.h
+++ b/host/libhackrf/src/hackrf.h
@@ -2385,6 +2385,20 @@ extern ADDAPI int ADDCALL hackrf_radio_write_register(
 	const uint8_t register_number,
 	const uint64_t value);
 
+/**
+ * Lock or unlock a radio configuration register.
+ *
+ * @param[in] device device to write
+ * @param[in] register_number register number to mask
+ * @param[out] locked locked state for the register
+ * @return @ref HACKRF_SUCCESS on success or @ref hackrf_error variant
+ * @ingroup debug
+ */
+extern ADDAPI int ADDCALL hackrf_radio_lock_register(
+	hackrf_device* device,
+	const uint8_t register_number,
+	const bool register_locked);
+
 #ifdef __cplusplus
 } // __cplusplus defined.
 #endif