diff --git a/STM32/cores/arduino/stm32/stm32_gpio_af.c b/STM32/cores/arduino/stm32/stm32_gpio_af.c
index 0bb88ab..b1e6904 100644
--- a/STM32/cores/arduino/stm32/stm32_gpio_af.c
+++ b/STM32/cores/arduino/stm32/stm32_gpio_af.c
@@ -61,6 +61,18 @@ void stm32AfI2SInit(const SPI_TypeDef *instance,
     stm32AfInit(chip_af_i2s_ck, sizeof(chip_af_i2s_ck) / sizeof(chip_af_i2s_ck[0]), instance, ckPort, ckPin, GPIO_MODE_AF_PP, GPIO_NOPULL);
 }
 
+void stm32AfI2SInitWithMck(const SPI_TypeDef *instance,
+    GPIO_TypeDef *sdPort, uint32_t sdPin,
+    GPIO_TypeDef *wsPort, uint32_t wsPin,
+    GPIO_TypeDef *ckPort, uint32_t ckPin,
+    GPIO_TypeDef *mckPort, uint32_t mckPin) {
+
+    stm32AfInit(chip_af_i2s_sd, sizeof(chip_af_i2s_sd) / sizeof(chip_af_i2s_sd[0]), instance, sdPort, sdPin, GPIO_MODE_AF_PP, GPIO_NOPULL);
+    stm32AfInit(chip_af_i2s_ws, sizeof(chip_af_i2s_ws) / sizeof(chip_af_i2s_ws[0]), instance, wsPort, wsPin, GPIO_MODE_AF_PP, GPIO_NOPULL);
+    stm32AfInit(chip_af_i2s_ck, sizeof(chip_af_i2s_ck) / sizeof(chip_af_i2s_ck[0]), instance, ckPort, ckPin, GPIO_MODE_AF_PP, GPIO_NOPULL);
+    stm32AfInit(chip_af_i2s_mck, sizeof(chip_af_i2s_mck) / sizeof(chip_af_i2s_mck[0]), instance, mckPort, mckPin, GPIO_MODE_AF_PP, GPIO_NOPULL);
+}
+
 void stm32AfI2CInit(const I2C_TypeDef *instance,
     GPIO_TypeDef *sdaPort, uint32_t sdaPin,
     GPIO_TypeDef *sclPort, uint32_t sclPin) {
diff --git a/STM32/cores/arduino/stm32/stm32_gpio_af.h b/STM32/cores/arduino/stm32/stm32_gpio_af.h
index c906de6..962f03f 100644
--- a/STM32/cores/arduino/stm32/stm32_gpio_af.h
+++ b/STM32/cores/arduino/stm32/stm32_gpio_af.h
@@ -56,6 +56,12 @@ void stm32AfI2SInit(const SPI_TypeDef *instance,
     GPIO_TypeDef *wsPort, uint32_t wsPin,
     GPIO_TypeDef *ckPort, uint32_t ckPin);
 
+void stm32AfI2SInitWithMck(const SPI_TypeDef *instance,
+    GPIO_TypeDef *sdPort, uint32_t sdPin,
+    GPIO_TypeDef *wsPort, uint32_t wsPin,
+    GPIO_TypeDef *ckPort, uint32_t ckPin,
+    GPIO_TypeDef *mckPort, uint32_t mckPin);
+
 void stm32AfI2CInit(const I2C_TypeDef *instance,
     GPIO_TypeDef *sdaPort, uint32_t sdaPin,
     GPIO_TypeDef *sclPort, uint32_t sclPin);
diff --git a/STM32/libraries/I2S/src/I2S.cpp b/STM32/libraries/I2S/src/I2S.cpp
index 151e7b8..77c5a4a 100644
--- a/STM32/libraries/I2S/src/I2S.cpp
+++ b/STM32/libraries/I2S/src/I2S.cpp
@@ -1,19 +1,25 @@
 #include "I2S.h"
 #include "stm32_gpio_af.h"
 
+#include "Arduino.h"
+
 I2SClass::I2SClass(SPI_TypeDef *instance) {
     handle.Instance = instance;
 }
 
 I2SClass::I2SClass(SPI_TypeDef *instance, uint8_t sd, uint8_t ws, uint8_t ck) {
     handle.Instance = instance;
+    stm32SetSD(sd);
+    stm32SetWS(ws);
+    stm32SetCK(ck);
+}
 
-    this->sdPort = variant_pin_list[sd].port;
-    this->sdPin = variant_pin_list[sd].pin_mask;
-    this->wsPort = variant_pin_list[ws].port;
-    this->wsPin = variant_pin_list[ws].pin_mask;
-    this->ckPort = variant_pin_list[ck].port;
-    this->ckPin = variant_pin_list[ck].pin_mask;
+I2SClass::I2SClass(SPI_TypeDef *instance, uint8_t sd, uint8_t ws, uint8_t ck, uint8_t mck) {
+    handle.Instance = instance;
+    stm32SetSD(sd);
+    stm32SetWS(ws);
+    stm32SetCK(ck);
+    stm32SetMCK(mck);
 }
 
 uint8_t I2SClass::begin(i2s_mode_t mode, uint32_t sampleRate, uint8_t bitsPerSample) {
@@ -37,7 +43,15 @@ uint8_t I2SClass::begin(i2s_mode_t mode, uint32_t sampleRate, uint8_t bitsPerSam
     if (handle.Instance == SPI6) __HAL_RCC_SPI6_CLK_ENABLE();
     #endif
 
-    stm32AfI2SInit(handle.Instance, sdPort, sdPin, wsPort, wsPin, ckPort, ckPin);
+
+
+    if (useMck) {
+        stm32AfI2SInitWithMck(handle.Instance, sdPort, sdPin, wsPort, wsPin, ckPort, ckPin, mckPort, mckPin);
+        handle.Init.MCLKOutput = I2S_MCLKOUTPUT_ENABLE;
+    } else {
+        stm32AfI2SInit(handle.Instance, sdPort, sdPin, wsPort, wsPin, ckPort, ckPin);
+        handle.Init.MCLKOutput = I2S_MCLKOUTPUT_DISABLE;
+    }
 
     if (mode == I2S_PHILIPS_MODE) {
         handle.Init.Standard = I2S_STANDARD_PHILIPS;
@@ -50,7 +64,6 @@ uint8_t I2SClass::begin(i2s_mode_t mode, uint32_t sampleRate, uint8_t bitsPerSam
     }
 
     handle.Init.Mode = I2S_MODE_MASTER_TX;
-    handle.Init.MCLKOutput = I2S_MCLKOUTPUT_DISABLE;
     handle.Init.AudioFreq = I2S_AUDIOFREQ_44K;
     handle.Init.CPOL = I2S_CPOL_LOW;
     handle.Init.ClockSource = I2S_CLOCK_PLL;
@@ -102,3 +115,24 @@ void I2SClass::write(uint16_t *data, uint16_t size) {
 void I2SClass::write32(uint32_t *data, uint16_t size) {
     HAL_I2S_Transmit(&handle, (uint16_t*)data, size, 1000);
 }
+
+void I2SClass::stm32SetSD(uint8_t sd) {
+    this->sdPort = variant_pin_list[sd].port;
+    this->sdPin = variant_pin_list[sd].pin_mask;
+}
+
+void I2SClass::stm32SetWS(uint8_t ws) {
+    this->wsPort = variant_pin_list[ws].port;
+    this->wsPin = variant_pin_list[ws].pin_mask;
+}
+
+void I2SClass::stm32SetCK(uint8_t ck) {
+    this->ckPort = variant_pin_list[ck].port;
+    this->ckPin = variant_pin_list[ck].pin_mask;
+}
+
+void I2SClass::stm32SetMCK(uint8_t mck) {
+    this->mckPort = variant_pin_list[mck].port;
+    this->mckPin = variant_pin_list[mck].pin_mask;
+    useMck = true;
+}
diff --git a/STM32/libraries/I2S/src/I2S.h b/STM32/libraries/I2S/src/I2S.h
index 5faf90f..7f4b49c 100644
--- a/STM32/libraries/I2S/src/I2S.h
+++ b/STM32/libraries/I2S/src/I2S.h
@@ -15,6 +15,8 @@ class I2SClass {
 
     I2SClass(SPI_TypeDef *instance, uint8_t sd, uint8_t ws, uint8_t ck);
 
+    I2SClass(SPI_TypeDef *instance, uint8_t sd, uint8_t ws, uint8_t ck, uint8_t mck);
+
     uint8_t begin(i2s_mode_t mode, uint32_t sampleRate, uint8_t bitsPerSample);
 
     void write(uint16_t data);
@@ -23,14 +25,23 @@ class I2SClass {
     void write(uint16_t *data, uint16_t size);
     void write32(uint32_t *data, uint16_t size);
 
+    void stm32SetSD(uint8_t sd);
+    void stm32SetWS(uint8_t ws);
+    void stm32SetCK(uint8_t ck);
+    void stm32SetMCK(uint8_t mck);
+
     I2S_HandleTypeDef handle;
 
+    bool useMck = false;
+
     GPIO_TypeDef *sdPort = NULL;
     uint32_t sdPin = 0;
     GPIO_TypeDef *wsPort = NULL;
     uint32_t wsPin = 0;
     GPIO_TypeDef *ckPort = NULL;
     uint32_t ckPin = 0;
+    GPIO_TypeDef *mckPort = NULL;
+    uint32_t mckPin = 0;
 };
 
 #endif