diff --git a/api/i_mini_servo_module.hpp b/api/i_mini_servo_module.hpp
index 457beff..204f037 100644
--- a/api/i_mini_servo_module.hpp
+++ b/api/i_mini_servo_module.hpp
@@ -11,7 +11,7 @@ using namespace std;
 class I_MiniServoModule {
  public:
   typedef enum { kNormalStop, kBreakStop } StopType_t;
-
+#pragma pack(1)
   typedef struct {
     u8  id;
     u8  status;
@@ -92,6 +92,8 @@ class I_MiniServoModule {
     s16 maxcurrent;
   } warning_limit_param_t;
 
+#pragma pack()
+
  public:
   virtual int32_t enable(u8 enable)                     = 0;
   virtual int32_t stop(u8 stop_type)                    = 0;
diff --git a/api/i_step_motor_ctrl_module.hpp b/api/i_step_motor_ctrl_module.hpp
index abf26b6..f8e139b 100644
--- a/api/i_step_motor_ctrl_module.hpp
+++ b/api/i_step_motor_ctrl_module.hpp
@@ -16,7 +16,7 @@ class I_StepMotorCtrlModule {
   /*******************************************************************************
    *                                   ACTION                                    *
    *******************************************************************************/
-
+#pragma pack(1)
   typedef struct {
     int32_t exec_status;
     int32_t tox;
@@ -88,6 +88,7 @@ class I_StepMotorCtrlModule {
     u32 speed;
     u32 dec;
   } run_to_zero_param_t;
+#pragma pack()
 
  public:
   virtual int32_t move_to(int32_t x, function<void(move_to_cb_status_t& status)> status_cb)                                         = 0;
diff --git a/api/i_xyrobot_ctrl_module.hpp b/api/i_xyrobot_ctrl_module.hpp
index c114301..2a77968 100644
--- a/api/i_xyrobot_ctrl_module.hpp
+++ b/api/i_xyrobot_ctrl_module.hpp
@@ -16,7 +16,7 @@ class I_XYRobotCtrlModule {
   /*******************************************************************************
    *                                   ACTION                                    *
    *******************************************************************************/
-
+#pragma pack(1)
   typedef struct {
     int32_t exec_status;
     int32_t tox;
@@ -94,6 +94,8 @@ class I_XYRobotCtrlModule {
     u32 dec;
   } run_to_zero_param_t;
 
+#pragma pack()
+
  public:
   virtual int32_t move_to(int32_t x, int32_t y, function<void(move_to_cb_status_t& status)> status_cb)                                         = 0;
   virtual int32_t move_by(int32_t dx, int32_t dy, function<void(move_by_cb_status_t& status)> status_cb)                                       = 0;