diff --git a/dcs.c b/dcs.c
index 4d93c9a..4615dc5 100644
--- a/dcs.c
+++ b/dcs.c
@@ -91,7 +91,7 @@ uint8_t DCS_GetCdcssCode(uint32_t Code)
 	return 0xFF;
 }
 
-uint8_t DCS_GetCtcssCode(uint16_t Code)
+uint8_t DCS_GetCtcssCode(int Code)
 {
 	unsigned int i;
 	uint8_t      Result = 0xFF;
diff --git a/dcs.h b/dcs.h
index b8dfdc0..873ddb6 100644
--- a/dcs.h
+++ b/dcs.h
@@ -39,7 +39,7 @@ extern const uint16_t DCS_Options[104];
 
 uint32_t DCS_GetGolayCodeWord(DCS_CodeType_t CodeType, uint8_t Option);
 uint8_t DCS_GetCdcssCode(uint32_t Code);
-uint8_t DCS_GetCtcssCode(uint16_t Code);
+uint8_t DCS_GetCtcssCode(int Code);
 
 #endif
 
diff --git a/driver/bk4819.c b/driver/bk4819.c
index 49ac4dc..384da6d 100644
--- a/driver/bk4819.c
+++ b/driver/bk4819.c
@@ -465,7 +465,7 @@ void BK4819_SetCTCSSFrequency(uint32_t FreqControlWord)
 	//                          freq(Hz) * 20.64888 for XTAL 13M/26M or
 	//                          freq(Hz) * 20.97152 for XTAL 12.8M/19.2M/25.6M/38.4M
 	//
-	BK4819_WriteRegister(BK4819_REG_07, BK4819_REG_07_MODE_CTC1 | (((FreqControlWord * 2064888u) + 500000u) / 1000000u));   // with rounding
+	BK4819_WriteRegister(BK4819_REG_07, BK4819_REG_07_MODE_CTC1 | (((FreqControlWord * 206488u) + 50000u) / 100000u));   // with rounding
 }
 
 // freq_10Hz is CTCSS Hz * 10
diff --git a/firmware.bin b/firmware.bin
index 005ff71..90d044b 100644
Binary files a/firmware.bin and b/firmware.bin differ
diff --git a/firmware.packed.bin b/firmware.packed.bin
index 8639629..364f0ce 100644
Binary files a/firmware.packed.bin and b/firmware.packed.bin differ