diff --git a/libraries/Wire/src/Wire.cpp b/libraries/Wire/src/Wire.cpp
index 500a348d81..a93367aa61 100644
--- a/libraries/Wire/src/Wire.cpp
+++ b/libraries/Wire/src/Wire.cpp
@@ -27,22 +27,6 @@ extern "C" {
 
 #include "Wire.h"
 
-// Initialize Class Variables //////////////////////////////////////////////////
-uint8_t *TwoWire::rxBuffer = nullptr;
-uint8_t TwoWire::rxBufferAllocated = 0;
-uint8_t TwoWire::rxBufferIndex = 0;
-uint8_t TwoWire::rxBufferLength = 0;
-
-uint8_t TwoWire::txAddress = 0;
-uint8_t *TwoWire::txBuffer = nullptr;
-uint8_t TwoWire::txBufferAllocated = 0;
-uint8_t TwoWire::txBufferIndex = 0;
-uint8_t TwoWire::txBufferLength = 0;
-
-uint8_t TwoWire::transmitting = 0;
-void (*TwoWire::user_onRequest)(void);
-void (*TwoWire::user_onReceive)(int);
-
 // Constructors ////////////////////////////////////////////////////////////////
 
 TwoWire::TwoWire()
@@ -81,6 +65,13 @@ void TwoWire::begin(uint8_t address, bool generalCall)
   txBufferLength = 0;
   resetTxBuffer();
 
+  rxBuffer = nullptr;
+  rxBufferAllocated = 0;
+  txAddress = 0;
+  txBuffer = nullptr;
+  txBufferAllocated = 0;
+  _i2c.__this = (void *)this;
+  user_onRequest = NULL;
   transmitting = 0;
 
   ownAddress = address << 1;
@@ -403,44 +394,51 @@ void TwoWire::flush(void)
 }
 
 // behind the scenes function that is called when data is received
-void TwoWire::onReceiveService(uint8_t *inBytes, int numBytes)
+void TwoWire::onReceiveService(i2c_t *obj)
 {
+  uint8_t *inBytes = (uint8_t *) obj->i2cTxRxBuffer;
+  int numBytes = obj->slaveRxNbData;
+
+  TwoWire *TW = (TwoWire *)(obj->__this);
+
   // don't bother if user hasn't registered a callback
-  if (user_onReceive) {
+  if (TW->user_onReceive) {
     // don't bother if rx buffer is in use by a master requestFrom() op
     // i know this drops data, but it allows for slight stupidity
     // meaning, they may not have read all the master requestFrom() data yet
-    if (rxBufferIndex >= rxBufferLength) {
+    if (TW->rxBufferIndex >= TW->rxBufferLength) {
 
-      allocateRxBuffer(numBytes);
+      TW->allocateRxBuffer(numBytes);
       // error if no memory block available to allocate the buffer
-      if (rxBuffer == nullptr) {
+      if (TW->rxBuffer == nullptr) {
         Error_Handler();
       }
 
       // copy twi rx buffer into local read buffer
       // this enables new reads to happen in parallel
-      memcpy(rxBuffer, inBytes, numBytes);
+      memcpy(TW->rxBuffer, inBytes, numBytes);
       // set rx iterator vars
-      rxBufferIndex = 0;
-      rxBufferLength = numBytes;
+      TW->rxBufferIndex = 0;
+      TW->rxBufferLength = numBytes;
       // alert user program
-      user_onReceive(numBytes);
+      TW->user_onReceive(numBytes);
     }
   }
 }
 
 // behind the scenes function that is called when data is requested
-void TwoWire::onRequestService(void)
+void TwoWire::onRequestService(i2c_t *obj)
 {
+  TwoWire *TW = (TwoWire *)(obj->__this);
+
   // don't bother if user hasn't registered a callback
-  if (user_onRequest) {
+  if (TW->user_onRequest) {
     // reset tx buffer iterator vars
     // !!! this will kill any pending pre-master sendTo() activity
-    txBufferIndex = 0;
-    txBufferLength = 0;
+    TW->txBufferIndex = 0;
+    TW->txBufferLength = 0;
     // alert user program
-    user_onRequest();
+    TW->user_onRequest();
   }
 }
 
diff --git a/libraries/Wire/src/Wire.h b/libraries/Wire/src/Wire.h
index b393ea5954..6a94b36a0e 100644
--- a/libraries/Wire/src/Wire.h
+++ b/libraries/Wire/src/Wire.h
@@ -37,28 +37,28 @@ extern "C" {
 
 class TwoWire : public Stream {
   private:
-    static uint8_t *rxBuffer;
-    static uint8_t rxBufferAllocated;
-    static uint8_t rxBufferIndex;
-    static uint8_t rxBufferLength;
+    uint8_t *rxBuffer;
+    uint8_t rxBufferAllocated;
+    uint8_t rxBufferIndex;
+    uint8_t rxBufferLength;
 
-    static uint8_t txAddress;
-    static uint8_t *txBuffer;
-    static uint8_t txBufferAllocated;
-    static uint8_t txBufferIndex;
-    static uint8_t txBufferLength;
+    uint8_t txAddress;
+    uint8_t *txBuffer;
+    uint8_t txBufferAllocated;
+    uint8_t txBufferIndex;
+    uint8_t txBufferLength;
 
-    static uint8_t transmitting;
+    uint8_t transmitting;
 
     uint8_t ownAddress;
     i2c_t _i2c;
 
-    static void (*user_onRequest)(void);
-    static void (*user_onReceive)(int);
-    static void onRequestService(void);
-    static void onReceiveService(uint8_t *, int);
+    void (*user_onRequest)(void);
+    void (*user_onReceive)(int);
+    static void onRequestService(i2c_t *);
+    static void onReceiveService(i2c_t *);
 
-    static void allocateRxBuffer(size_t length);
+    void allocateRxBuffer(size_t length);
     void allocateTxBuffer(size_t length);
 
     void resetRxBuffer(void);
diff --git a/libraries/Wire/src/utility/twi.c b/libraries/Wire/src/utility/twi.c
index 7e2420962d..69a5d17fc4 100644
--- a/libraries/Wire/src/utility/twi.c
+++ b/libraries/Wire/src/utility/twi.c
@@ -948,7 +948,7 @@ i2c_t *get_i2c_obj(I2C_HandleTypeDef *hi2c)
   * @param  function: callback function to use
   * @retval None
   */
-void i2c_attachSlaveRxEvent(i2c_t *obj, void (*function)(uint8_t *, int))
+void i2c_attachSlaveRxEvent(i2c_t *obj, void (*function)(i2c_t *))
 {
   if ((obj != NULL) && (function != NULL)) {
     obj->i2c_onSlaveReceive = function;
@@ -961,7 +961,7 @@ void i2c_attachSlaveRxEvent(i2c_t *obj, void (*function)(uint8_t *, int))
   * @param  function: callback function to use
   * @retval None
   */
-void i2c_attachSlaveTxEvent(i2c_t *obj, void (*function)(void))
+void i2c_attachSlaveTxEvent(i2c_t *obj, void (*function)(i2c_t *))
 {
   if ((obj != NULL) && (function != NULL)) {
     obj->i2c_onSlaveTransmit = function;
@@ -986,7 +986,7 @@ void HAL_I2C_AddrCallback(I2C_HandleTypeDef *hi2c, uint8_t TransferDirection, ui
       obj->slaveMode = SLAVE_MODE_TRANSMIT;
 
       if (obj->i2c_onSlaveTransmit != NULL) {
-        obj->i2c_onSlaveTransmit();
+        obj->i2c_onSlaveTransmit(obj);
       }
 #if defined(STM32F0xx) || defined(STM32F1xx) || defined(STM32F2xx) || defined(STM32F3xx) ||\
     defined(STM32F4xx) || defined(STM32L0xx) || defined(STM32L1xx) || defined(STM32MP1xx)
@@ -1026,7 +1026,7 @@ void HAL_I2C_ListenCpltCallback(I2C_HandleTypeDef *hi2c)
   /*  Previous master transaction now ended, so inform upper layer if needed
    *  then prepare for listening to next request */
   if ((obj->slaveMode == SLAVE_MODE_RECEIVE) && (obj->slaveRxNbData != 0)) {
-    obj->i2c_onSlaveReceive((uint8_t *) obj->i2cTxRxBuffer, obj->slaveRxNbData);
+    obj->i2c_onSlaveReceive(obj);
   }
   obj->slaveMode = SLAVE_MODE_LISTEN;
   obj->slaveRxNbData = 0;
diff --git a/libraries/Wire/src/utility/twi.h b/libraries/Wire/src/utility/twi.h
index 07d22a0949..0d12e296b9 100644
--- a/libraries/Wire/src/utility/twi.h
+++ b/libraries/Wire/src/utility/twi.h
@@ -99,6 +99,7 @@ struct i2c_s {
      */
   I2C_TypeDef  *i2c;
   I2C_HandleTypeDef handle;
+  void *__this;
   PinName sda;
   PinName scl;
   IRQn_Type irq;
@@ -106,8 +107,8 @@ struct i2c_s {
   IRQn_Type irqER;
 #endif /* !STM32F0xx && !STM32G0xx && !STM32L0xx */
   volatile int slaveRxNbData; // Number of accumulated bytes received in Slave mode
-  void (*i2c_onSlaveReceive)(uint8_t *, int);
-  void (*i2c_onSlaveTransmit)(void);
+  void (*i2c_onSlaveReceive)(i2c_t *);
+  void (*i2c_onSlaveTransmit)(i2c_t *);
   volatile uint8_t i2cTxRxBuffer[I2C_TXRX_BUFFER_SIZE];
   volatile uint8_t i2cTxRxBufferSize;
   volatile uint8_t slaveMode;
@@ -138,8 +139,8 @@ i2c_status_e i2c_master_read(i2c_t *obj, uint8_t dev_address, uint8_t *data, uin
 
 i2c_status_e i2c_IsDeviceReady(i2c_t *obj, uint8_t devAddr, uint32_t trials);
 
-void i2c_attachSlaveRxEvent(i2c_t *obj, void (*function)(uint8_t *, int));
-void i2c_attachSlaveTxEvent(i2c_t *obj, void (*function)(void));
+void i2c_attachSlaveRxEvent(i2c_t *obj, void (*function)(i2c_t *));
+void i2c_attachSlaveTxEvent(i2c_t *obj, void (*function)(i2c_t *));
 
 #ifdef __cplusplus
 }