diff --git a/firmware/common/hackrf_core.c b/firmware/common/hackrf_core.c
index d1be02e7..7246d222 100644
--- a/firmware/common/hackrf_core.c
+++ b/firmware/common/hackrf_core.c
@@ -49,6 +49,9 @@ bool set_fracrate(const float freq) {
 
 	if(a != div){
 		uint32_t j=0,k=1,l=1,m=1;
+
+        si5351c_set_int_mode(0, 0);
+
 		while (k <= 0xFFFF && m <= 0xFFFF){
 			float n = (float)(j+l)/(k+m);
 			if( x == n){
@@ -77,6 +80,10 @@ bool set_fracrate(const float freq) {
 			b=j; c=k;
 		}
 	} else {
+        if(a & 0x1) // odd integer, needs frac mode
+            si5351c_set_int_mode(0, 0);
+        else
+            si5351c_set_int_mode(0, 1);
 		b=0; c=1;
 	}
 
diff --git a/firmware/common/si5351c.c b/firmware/common/si5351c.c
index 6cc0d253..e661fbc0 100644
--- a/firmware/common/si5351c.c
+++ b/firmware/common/si5351c.c
@@ -249,3 +249,21 @@ void si5351c_configure_clock_control()
 	uint8_t data[] = { 3, 0xC8 };
  	si5351c_write(data, sizeof(data));
  }
+
+
+ void si5351c_set_int_mode(const uint_fast8_t ms_number, const uint_fast8_t on){
+  uint8_t data[] = {16, 0};
+
+  if(ms_number < 8){
+      data[0] = 16 + ms_number;
+      data[1] = si5351c_read_single(data[0]);
+
+      if(on)
+          data[1] |= SI5351C_CLK_INT_MODE;
+      else
+          data[1] &= ~(SI5351C_CLK_INT_MODE);
+
+      si5351c_write(data, 2);
+  }
+
+ }
diff --git a/firmware/common/si5351c.h b/firmware/common/si5351c.h
index 12f1dc3a..a2867438 100644
--- a/firmware/common/si5351c.h
+++ b/firmware/common/si5351c.h
@@ -67,6 +67,7 @@ void si5351c_configure_multisynth(const uint_fast8_t ms_number,
     	const uint_fast8_t r_div);
 void si5351c_configure_clock_control();
 void si5351c_enable_clock_outputs();
+void si5351c_set_int_mode(const uint_fast8_t ms_number, const uint_fast8_t on);
 
 void si5351c_write_single(uint8_t reg, uint8_t val);
 uint8_t si5351c_read_single(uint8_t reg);
diff --git a/host/hackrf-tools/src/hackrf_si5351c.c b/host/hackrf-tools/src/hackrf_si5351c.c
index f9e86910..0a447d45 100644
--- a/host/hackrf-tools/src/hackrf_si5351c.c
+++ b/host/hackrf-tools/src/hackrf_si5351c.c
@@ -109,53 +109,60 @@ int dump_multisynth_config(hackrf_device* device, const uint_fast8_t ms_number)
 	uint32_t p1,p2,p3,r_div;
 	uint_fast8_t div_lut[] = {1,2,4,8,16,32,64,128};
 
-    printf("MS%d:", ms_number);
-    if(ms_number <6){
-        reg_base = 42 + (ms_number * 8);
-        for(i=0; i<8; i++) {
-            uint_fast8_t reg_number = reg_base + i;
-            int result = hackrf_si5351c_read(device, reg_number, &parameters[i]);
-            if( result != HACKRF_SUCCESS ) {
-                return result;
-            }
-        }
+	printf("MS%d:", ms_number);
+	if(ms_number <6){
+		reg_base = 42 + (ms_number * 8);
+		for(i=0; i<8; i++) {
+			uint_fast8_t reg_number = reg_base + i;
+			int result = hackrf_si5351c_read(device, reg_number, &parameters[i]);
+			if( result != HACKRF_SUCCESS ) {
+				return result;
+			}
+		}
 
-        p1 =
-              (parameters[2] & 0x03 << 16)
-            | (parameters[3] << 8)
-            | parameters[4]
-            ;
-        p2 =
-              (parameters[5] & 0x0F << 16)
-            | (parameters[6] << 8)
-            | parameters[7]
-            ;
-        p3 =
-              (parameters[5] & 0xF0 << 12)
-            | (parameters[0] << 8)
-            |  parameters[1]
-            ;
-        r_div =
-            (parameters[2] >> 4) & 0x7
-            ;
+		p1 =
+			  (parameters[2] & 0x03 << 16)
+			| (parameters[3] << 8)
+			| parameters[4]
+			;
+		p2 =
+			  (parameters[5] & 0x0F << 16)
+			| (parameters[6] << 8)
+			| parameters[7]
+			;
+		p3 =
+			  (parameters[5] & 0xF0 << 12)
+			| (parameters[0] << 8)
+			|  parameters[1]
+			;
+		r_div =
+			(parameters[2] >> 4) & 0x7
+			;
 
-        printf("\tp1 = %u\n", p1);
-        printf("\tp2 = %u\n", p2);
-        printf("\tp3 = %u\n", p3);
-    } else {
-        // MS6 and 7 are integer only
-        reg_base = 90;
-        for(i=0; i<3; i++) {
-            uint_fast8_t reg_number = reg_base + i;
-            int result = hackrf_si5351c_read(device, reg_number, &parameters[i]);
-            if( result != HACKRF_SUCCESS ) {
-                return result;
-            }
-        }
+		printf("\tp1 = %u\n", p1);
+		printf("\tp2 = %u\n", p2);
+		printf("\tp3 = %u\n", p3);
+		if(p3)
+			printf("\tOutput (800Mhz PLL): %#.10f Mhz\n", (800 / (float)((p1*p3 + p2 + 512*p3)/(128*p3))) / div_lut[r_div] );
+	} else {
+		// MS6 and 7 are integer only
+		unsigned int parms;
+		reg_base = 90;
 
-        r_div = (ms_number == 6) ? parameters[2] & 0x7 : parameters[2] & 0x70 >> 4 ;
-		printf("\tp1_int = %u\n", (ms_number == 6) ? parameters[0] : parameters[1]);
-    }
+		for(i=0; i<3; i++) {
+			uint_fast8_t reg_number = reg_base + i;
+			int result = hackrf_si5351c_read(device, reg_number, &parameters[i]);
+			if( result != HACKRF_SUCCESS ) {
+				return result;
+			}
+		}
+
+		r_div = (ms_number == 6) ? parameters[2] & 0x7 : parameters[2] & 0x70 >> 4 ;
+		parms = (ms_number == 6) ? parameters[0] : parameters[1];
+		printf("\tp1_int = %u\n", parms);
+		if(parms)
+			printf("\tOutput (800Mhz PLL): %#.10f Mhz\n", (800.0f / parms) / div_lut[r_div] );
+	}
 	printf("\toutput divider = %u\n", div_lut[r_div]);
 	
 	return HACKRF_SUCCESS;
@@ -236,6 +243,6 @@ int main(int argc, char** argv) {
 	}
 	
 	hackrf_exit();
-    
-    return 0;
+	
+	return 0;
 }
diff --git a/host/libhackrf/src/hackrf.c b/host/libhackrf/src/hackrf.c
index b09e5ac0..49a89fc9 100644
--- a/host/libhackrf/src/hackrf.c
+++ b/host/libhackrf/src/hackrf.c
@@ -770,8 +770,6 @@ typedef struct {
 
 int ADDCALL hackrf_set_fracrate(hackrf_device* device, const float freq_mhz)
 {
-	uint32_t l_freq_mhz;
-	uint32_t l_freq_hz;
 	set_fracrate_params_t set_fracrate_params;
 	uint8_t length;
 	int result;