diff --git a/components/freemodbus/port/porttimer.c b/components/freemodbus/port/porttimer.c
index 4898e0ca0..95ecf0f3a 100644
--- a/components/freemodbus/port/porttimer.c
+++ b/components/freemodbus/port/porttimer.c
@@ -50,6 +50,7 @@
 #include "mbport.h"
 #include "driver/timer.h"
 #include "port_serial_slave.h"
+#include "sdkconfig.h"
 
 #ifdef CONFIG_FMB_TIMER_PORT_ENABLED
 
@@ -63,6 +64,7 @@
 
 static const USHORT usTimerIndex = CONFIG_FMB_TIMER_INDEX; // Modbus Timer index used by stack
 static const USHORT usTimerGroupIndex = CONFIG_FMB_TIMER_GROUP; // Modbus Timer group index used by stack
+static timer_isr_handle_t xTimerIntHandle;                      // Timer interrupt handle
 
 /* ----------------------- Start implementation -----------------------------*/
 static void IRAM_ATTR vTimerGroupIsr(void *param)
@@ -109,7 +111,8 @@ BOOL xMBPortTimersInit(USHORT usTim1Timerout50us)
                     "failure to set alarm failure, timer_set_alarm_value() returned (0x%x).",
                     (uint32_t)xErr);
     // Register ISR for timer
-    xErr = timer_isr_register(usTimerGroupIndex, usTimerIndex, vTimerGroupIsr, (void*)(uint32_t)usTimerIndex, ESP_INTR_FLAG_IRAM, NULL);
+    xErr = timer_isr_register(usTimerGroupIndex, usTimerIndex, vTimerGroupIsr,
+                                (void*)(uint32_t)usTimerIndex, ESP_INTR_FLAG_LOWMED, &xTimerIntHandle);
     MB_PORT_CHECK((xErr == ESP_OK), FALSE,
                     "timer set value failure, timer_isr_register() returned (0x%x).",
                     (uint32_t)xErr);
@@ -142,6 +145,6 @@ void vMBPortTimerClose(void)
 #ifdef CONFIG_FMB_TIMER_PORT_ENABLED
     ESP_ERROR_CHECK(timer_pause(usTimerGroupIndex, usTimerIndex));
     ESP_ERROR_CHECK(timer_disable_intr(usTimerGroupIndex, usTimerIndex));
+    ESP_ERROR_CHECK(esp_intr_free(xTimerIntHandle));
 #endif
 }
-
diff --git a/components/freemodbus/port/porttimer_m.c b/components/freemodbus/port/porttimer_m.c
index af0ded085..7a4897d10 100644
--- a/components/freemodbus/port/porttimer_m.c
+++ b/components/freemodbus/port/porttimer_m.c
@@ -51,16 +51,15 @@
 #define MB_TIMER_WITH_RELOAD    (1)
 
 // Timer group and timer number to measure time (configurable in KConfig)
-#define MB_TIMER_INDEX CONFIG_FMB_TIMER_INDEX
-#define MB_TIMER_GROUP CONFIG_FMB_TIMER_GROUP
-
-#define MB_TIMER_IO_LED 0
+#define MB_TIMER_INDEX          (CONFIG_FMB_TIMER_INDEX)
+#define MB_TIMER_GROUP          (CONFIG_FMB_TIMER_GROUP)
 
 /* ----------------------- Variables ----------------------------------------*/
 static USHORT usT35TimeOut50us;
 
 static const USHORT usTimerIndex = MB_TIMER_INDEX;      // Initialize Modbus Timer index used by stack,
 static const USHORT usTimerGroupIndex = MB_TIMER_GROUP; // Timer group index used by stack
+static timer_isr_handle_t xTimerIntHandle;              // Timer interrupt handle
 
 /* ----------------------- static functions ---------------------------------*/
 
@@ -110,7 +109,7 @@ BOOL xMBMasterPortTimersInit(USHORT usTimeOut50us)
                     (uint32_t)xErr);
     // Register ISR for timer
     xErr = timer_isr_register(usTimerGroupIndex, usTimerIndex,
-                                vTimerGroupIsr, (void*)(uint32_t)usTimerIndex, ESP_INTR_FLAG_IRAM, NULL);
+                                vTimerGroupIsr, (void*)(uint32_t)usTimerIndex, ESP_INTR_FLAG_LOWMED, &xTimerIntHandle);
     MB_PORT_CHECK((xErr == ESP_OK), FALSE,
                     "timer set value failure, timer_isr_register() returned (0x%x).",
                     (uint32_t)xErr);
@@ -146,7 +145,7 @@ static BOOL xMBMasterPortTimersEnable(USHORT usTimerTics50us)
     MB_PORT_CHECK((xErr == ESP_OK), FALSE,
                             "timer start failure, timer_start() returned (0x%x).",
                             (uint32_t)xErr);
-    //ESP_LOGD(MB_PORT_TAG,"%s Init timer.", __func__);
+    ESP_LOGD(MB_PORT_TAG,"%s Init timer.", __func__);
     return TRUE;
 }
 
@@ -193,4 +192,5 @@ void vMBMasterPortTimerClose(void)
 {
     ESP_ERROR_CHECK(timer_pause(usTimerGroupIndex, usTimerIndex));
     ESP_ERROR_CHECK(timer_disable_intr(usTimerGroupIndex, usTimerIndex));
-}
+    ESP_ERROR_CHECK(esp_intr_free(xTimerIntHandle));
+}
\ No newline at end of file
diff --git a/components/freemodbus/serial_master/modbus_controller/mbc_serial_master.c b/components/freemodbus/serial_master/modbus_controller/mbc_serial_master.c
index 30aae200f..b162312f9 100644
--- a/components/freemodbus/serial_master/modbus_controller/mbc_serial_master.c
+++ b/components/freemodbus/serial_master/modbus_controller/mbc_serial_master.c
@@ -140,6 +140,7 @@ static esp_err_t mbc_serial_master_destroy(void)
     MB_MASTER_CHECK((mb_error == MB_ENOERR), ESP_ERR_INVALID_STATE,
             "mb stack close failure returned (0x%x).", (uint32_t)mb_error);
     free(mbm_interface_ptr); // free the memory allocated for options
+    mbm_interface_ptr = NULL;
     return ESP_OK;
 }
 
diff --git a/components/freemodbus/serial_slave/modbus_controller/mbc_serial_slave.c b/components/freemodbus/serial_slave/modbus_controller/mbc_serial_slave.c
index 5c6b05f37..6a125d997 100644
--- a/components/freemodbus/serial_slave/modbus_controller/mbc_serial_slave.c
+++ b/components/freemodbus/serial_slave/modbus_controller/mbc_serial_slave.c
@@ -133,7 +133,7 @@ static esp_err_t mbc_serial_slave_destroy(void)
     MB_SLAVE_CHECK((mb_error == MB_ENOERR), ESP_ERR_INVALID_STATE,
             "mb stack close failure returned (0x%x).", (uint32_t)mb_error);
     free(mbs_interface_ptr);
-
+    mbs_interface_ptr = NULL;
     return ESP_OK;
 }
 
diff --git a/examples/protocols/modbus_master/main/sense_modbus.c b/examples/protocols/modbus_master/main/sense_modbus.c
index 8d1ab3539..c2830fe73 100644
--- a/examples/protocols/modbus_master/main/sense_modbus.c
+++ b/examples/protocols/modbus_master/main/sense_modbus.c
@@ -59,16 +59,16 @@ static void* sense_modbus_get_param_data(const mb_parameter_descriptor_t* param_
        switch(param_descriptor->mb_param_type)
        {
            case MB_PARAM_HOLDING:
-               instance_ptr = (void*)(&holding_reg_params + param_descriptor->param_offset - 1);
+               instance_ptr = (void*)((uint32_t)&holding_reg_params + param_descriptor->param_offset - 1);
                break;
            case MB_PARAM_INPUT:
-               instance_ptr = (void*)(&input_reg_params + param_descriptor->param_offset - 1);
+               instance_ptr = (void*)((uint32_t)&input_reg_params + param_descriptor->param_offset - 1);
                break;
            case MB_PARAM_COIL:
-               instance_ptr = (void*)(&coil_reg_params + param_descriptor->param_offset - 1);
+               instance_ptr = (void*)((uint32_t)&coil_reg_params + param_descriptor->param_offset - 1);
                break;
            case MB_PARAM_DISCRETE:
-               instance_ptr = (void*)(&discrete_reg_params + param_descriptor->param_offset - 1);
+               instance_ptr = (void*)((uint32_t)&discrete_reg_params + param_descriptor->param_offset - 1);
                break;
            default:
                instance_ptr = NULL;