diff --git a/src/main.c b/src/main.c
index d4cd731..f534c1a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -16,7 +16,6 @@
 #include <hardware/regs/clocks.h>
 #include <hardware/structs/bus_ctrl.h>
 
-#include <math.h>
 #include <stdio.h>
 #include <limits.h>
 #include <stdlib.h>
@@ -234,13 +233,11 @@ static void init_adder()
 	pio_sm_init(PIO, SM_SIN, origin_adder, &pc);
 }
 
-#define STEP_BASE ((UINT_MAX + 1.0) / CLK_SYS_HZ)
-
 static void lo_generate_phase(uint32_t *buf, size_t len, uint32_t step, uint32_t phase)
 {
-	for (size_t i = 0; i < len; i++) {
-		uint32_t bits = 0;
+	uint32_t bits = 0;
 
+	for (size_t i = 0; i < len; i++) {
 		for (int j = 0; j < 32; j++) {
 			bits <<= 1;
 			bits |= phase >> 31;
@@ -251,16 +248,9 @@ static void lo_generate_phase(uint32_t *buf, size_t len, uint32_t step, uint32_t
 	}
 }
 
-static void rx_lo_init(double req_freq, bool align)
+static void rx_lo_init(uint32_t freq)
 {
-	const double step_hz = (double)CLK_SYS_HZ / ((8 << LO_BITS_DEPTH) / 2.0);
-	double freq = req_freq;
-
-	if (align)
-		freq = round(freq / step_hz) * step_hz;
-
-	uint32_t step = STEP_BASE * freq;
-
+	uint32_t step = ((uint64_t)freq << 32) / (uint64_t)CLK_SYS_HZ;
 	lo_generate_phase(lo_cos, LO_WORDS, step, COS_PHASE);
 	lo_generate_phase(lo_sin, LO_WORDS, step, SIN_PHASE);
 }
@@ -535,13 +525,13 @@ static void run_command(uint8_t cmd, uint32_t arg)
 	if (0x01 == cmd) {
 		/* Tune to a new center frequency */
 		frequency = arg;
-		rx_lo_init(frequency + sample_rate, true);
+		rx_lo_init(frequency + sample_rate);
 	} else if (0x02 == cmd) {
 		/* Set the rate at which IQ sample pairs are sent */
 		sample_rate = arg;
 		gain = BASE_GAIN / (CLK_SYS_HZ / sample_rate / 2);
 		dma_timer_set_fraction(dma_t_samp, 1, CLK_SYS_HZ / (sample_rate * DECIMATE));
-		rx_lo_init(frequency + sample_rate, true);
+		rx_lo_init(frequency + sample_rate);
 	}
 }
 
@@ -632,7 +622,7 @@ int main()
 
 	queue_init(&iq_queue, sizeof(uint8_t *), IQ_QUEUE_LEN);
 
-	rx_lo_init(frequency + sample_rate, true);
+	rx_lo_init(frequency + sample_rate);
 
 	/* We need to have the sampling timer ready. */
 	dma_t_samp = dma_claim_unused_timer(true);