diff --git a/testhal/STM32/I2C/lis3.c b/testhal/STM32/I2C/lis3.c
index 00bb712a1..14616478b 100644
--- a/testhal/STM32/I2C/lis3.c
+++ b/testhal/STM32/I2C/lis3.c
@@ -19,7 +19,7 @@ static i2cblock_t accel_rx_data[ACCEL_RX_DEPTH];
 static i2cblock_t accel_tx_data[ACCEL_TX_DEPTH];
 
 /* Error trap */
-static void i2c_lis3_error_cb(I2CDriver *i2cp, I2CSlaveConfig *i2cscfg){
+static void i2c_lis3_error_cb(I2CDriver *i2cp, const I2CSlaveConfig *i2cscfg){
   (void)i2cscfg;
   int status = 0;
   status = i2cp->id_i2c->SR1;
@@ -62,7 +62,7 @@ static msg_t I2CAccelThread(void *arg) {
 }
 
 /* This callback raise up when transfer finished */
-static void i2c_lis3_cb(I2CDriver *i2cp, I2CSlaveConfig *i2cscfg){
+static void i2c_lis3_cb(I2CDriver *i2cp, const I2CSlaveConfig *i2cscfg){
   (void) i2cp;
   // only wake up processing thread
   if (i2c_accel_tp != NULL) {
diff --git a/testhal/STM32/I2C/max1236.c b/testhal/STM32/I2C/max1236.c
index ed9d12ca6..2ba5f89b0 100644
--- a/testhal/STM32/I2C/max1236.c
+++ b/testhal/STM32/I2C/max1236.c
@@ -18,7 +18,7 @@ static uint16_t ch1 = 0, ch2 = 0, ch3 = 0, ch4 = 0;
 
 
 /* Error trap */
-static void i2c_max1236_error_cb(I2CDriver *i2cp, I2CSlaveConfig *i2cscfg){
+static void i2c_max1236_error_cb(I2CDriver *i2cp, const I2CSlaveConfig *i2cscfg){
   (void)i2cscfg;
   int status = 0;
   status = i2cp->id_i2c->SR1;
@@ -27,7 +27,7 @@ static void i2c_max1236_error_cb(I2CDriver *i2cp, I2CSlaveConfig *i2cscfg){
 
 
 /* This callback raise up when transfer finished */
-static void i2c_max1236_cb(I2CDriver *i2cp, I2CSlaveConfig *i2cscfg){
+static void i2c_max1236_cb(I2CDriver *i2cp, const I2CSlaveConfig *i2cscfg){
   (void)*i2cp;
   /* get ADC data */
   ch1 = ((i2cscfg->rxbuf[0] & 0xF) << 8) + i2cscfg->rxbuf[1];
diff --git a/testhal/STM32/I2C/tmp75.c b/testhal/STM32/I2C/tmp75.c
index 6744fe325..1d1432601 100644
--- a/testhal/STM32/I2C/tmp75.c
+++ b/testhal/STM32/I2C/tmp75.c
@@ -19,7 +19,7 @@ static i2cblock_t tmp75_tx_data[TMP75_TX_DEPTH];
 static int16_t temperature = 0;
 
 // Simple error trap
-static void i2c_tmp75_error_cb(I2CDriver *i2cp, I2CSlaveConfig *i2cscfg){
+static void i2c_tmp75_error_cb(I2CDriver *i2cp, const I2CSlaveConfig *i2cscfg){
   (void)i2cscfg;
   int status = 0;
   status = i2cp->id_i2c->SR1;
@@ -27,7 +27,7 @@ static void i2c_tmp75_error_cb(I2CDriver *i2cp, I2CSlaveConfig *i2cscfg){
 }
 
 /* This callback raise up when transfer finished */
-static void i2c_tmp75_cb(I2CDriver *i2cp, I2CSlaveConfig *i2cscfg){
+static void i2c_tmp75_cb(I2CDriver *i2cp, const I2CSlaveConfig *i2cscfg){
   (void)*i2cp;
   /* store temperature value */
   temperature = (i2cscfg->rxbuf[0] << 8) + i2cscfg->rxbuf[1];