diff --git a/firmware/common/rffc5071.c b/firmware/common/rffc5071.c
index 67bbd023..74de7b4e 100644
--- a/firmware/common/rffc5071.c
+++ b/firmware/common/rffc5071.c
@@ -1,5 +1,6 @@
 /*
  * Copyright 2012 Michael Ossmann
+ * Copyright 2014 Jared Boone <jared@sharebrained.com>
  *
  * This file is part of HackRF.
  *
@@ -407,12 +408,12 @@ void rffc5071_enable(void)  {
 #define REF_FREQ 50
 
 /* configure frequency synthesizer in integer mode (lo in MHz) */
-uint32_t rffc5071_config_synth_int(uint16_t lo) {
+uint64_t rffc5071_config_synth_int(uint16_t lo) {
 	uint8_t lodiv;
 	uint16_t fvco;
 	uint8_t fbkdiv;
 	uint16_t n;
-	uint32_t tune_freq_hz;
+	uint64_t tune_freq_hz;
 	uint16_t p1nmsb;
 	uint8_t p1nlsb;
 	
@@ -448,7 +449,7 @@ uint32_t rffc5071_config_synth_int(uint16_t lo) {
 	p1nlsb = (tmp_n >> 5ULL) & 0xff;
 	
 	//~ tune_freq = REF_FREQ*tmp_n*fbkdiv/lodiv / (1 << 29);
-	tune_freq_hz = (uint32_t)(REF_FREQ*tmp_n*fbkdiv/lodiv * 1000*1000 / (1 << 29ULL));
+	tune_freq_hz = REF_FREQ*tmp_n*fbkdiv/lodiv * 1000*1000 / (1 << 29ULL);
 	LOG("# lo=%d n_lo=%d lodiv=%d fvco=%d fbkdiv=%d n=%d tune_freq_hz=%d\n",
 	    lo, n_lo, lodiv, fvco, fbkdiv, n, tune_freq);
 
@@ -472,7 +473,7 @@ uint32_t rffc5071_config_synth_int(uint16_t lo) {
 }
 
 /* !!!!!!!!!!! hz is currently ignored !!!!!!!!!!! */
-uint32_t rffc5071_set_frequency(uint16_t mhz) {
+uint64_t rffc5071_set_frequency(uint16_t mhz) {
 	uint32_t tune_freq;
 
 	rffc5071_disable();
diff --git a/firmware/common/rffc5071.h b/firmware/common/rffc5071.h
index cd403771..98c31a3e 100644
--- a/firmware/common/rffc5071.h
+++ b/firmware/common/rffc5071.h
@@ -1,5 +1,6 @@
 /*
  * Copyright 2012 Michael Ossmann
+ * Copyright 2014 Jared Boone <jared@sharebrained.com>
  *
  * This file is part of HackRF.
  *
@@ -49,7 +50,7 @@ extern void rffc5071_reg_write(uint8_t r, uint16_t v);
 extern void rffc5071_regs_commit(void);
 
 /* Set frequency (MHz). */
-extern uint32_t rffc5071_set_frequency(uint16_t mhz);
+extern uint64_t rffc5071_set_frequency(uint16_t mhz);
 
 /* Set up rx only, tx only, or full duplex. Chip should be disabled
  * before _tx, _rx, or _rxtx are called. */
diff --git a/firmware/common/tuning.c b/firmware/common/tuning.c
index 66a01d76..9f16e391 100644
--- a/firmware/common/tuning.c
+++ b/firmware/common/tuning.c
@@ -51,7 +51,7 @@ bool set_freq(const uint64_t freq)
 	bool success;
 	uint32_t RFFC5071_freq_mhz;
 	uint32_t MAX2837_freq_hz;
-	uint32_t real_RFFC5071_freq_hz;
+	uint64_t real_RFFC5071_freq_hz;
 	uint32_t tmp_hz;
 
 	const uint32_t freq_mhz = freq / 1000000;
diff --git a/firmware/hackrf_usb/usb_api_transceiver.c b/firmware/hackrf_usb/usb_api_transceiver.c
index 1dd071c5..bb1c2408 100644
--- a/firmware/hackrf_usb/usb_api_transceiver.c
+++ b/firmware/hackrf_usb/usb_api_transceiver.c
@@ -75,7 +75,7 @@ usb_request_status_t usb_vendor_request_set_freq(
 		return USB_REQUEST_STATUS_OK;
 	} else if (stage == USB_TRANSFER_STAGE_DATA) 
 	{
-		const uint64_t freq = set_freq_params.freq_mhz * 1000000 + set_freq_params.freq_hz;
+		const uint64_t freq = set_freq_params.freq_mhz * 1000000ULL + set_freq_params.freq_hz;
 		if( set_freq(freq) ) 
 		{
 			usb_transfer_schedule_ack(endpoint->in);