diff --git a/src/nh_ctrl_api.c b/src/nh_ctrl_api.c
index d4745f9..ec74308 100644
--- a/src/nh_ctrl_api.c
+++ b/src/nh_ctrl_api.c
@@ -10,11 +10,11 @@
 #define NH_COMMAND_TIMEOUT_MSEC 30000
 #define NH_COMMAND_REQ_MEM_SIZE 256
 
-#define NH_CTRL_API_CREATE_ALLOCATOR(allocator_name)     \
-    ProtobufCAllocator allocator_name = {                \
-        .alloc          = nh_ctrl_api_protobuf_allocate, \
-        .free           = nh_ctrl_api_protobuf_free,     \
-        .allocator_data = api,                           \
+#define NH_CTRL_API_CREATE_ALLOCATOR(allocator_name, allocator_ctx) \
+    ProtobufCAllocator allocator_name = {                           \
+        .alloc          = nh_ctrl_api_protobuf_allocate,            \
+        .free           = nh_ctrl_api_protobuf_free,                \
+        .allocator_data = allocator_ctx,                            \
     }
 
 #define NH_CTRL_API_TAKE_SEM(s_api, timeout)  s_api->osa->sem_take(s_api->osa->user_data, s_api->p_sem_req, timeout)
@@ -61,7 +61,7 @@ free_sem_req:
 nh_ret_t nh_ctrl_api_get_mac_address(nh_ctrl_api_t *api, uint8_t *mac_addr, nh_ctrl_wifi_mode_t mode) {
     nh_ret_t ret = NH_RET_SUCCESS;
 
-    NH_CTRL_API_CREATE_ALLOCATOR(c_alloc);
+    NH_CTRL_API_CREATE_ALLOCATOR(c_alloc, api);
     ret = NH_CTRL_API_TAKE_SEM(api, NH_COMMAND_TIMEOUT_MSEC);
     if (ret != NH_RET_SUCCESS) return ret;
 
@@ -107,7 +107,7 @@ give_sem_exit:
 nh_ret_t nh_ctrl_api_get_ap_scan_list(nh_ctrl_api_t *api, nh_ctrl_api_ap_scan_list_cb_t cb) {
     nh_ret_t ret = NH_RET_SUCCESS;
 
-    NH_CTRL_API_CREATE_ALLOCATOR(c_alloc);
+    NH_CTRL_API_CREATE_ALLOCATOR(c_alloc, api);
     ret = NH_CTRL_API_TAKE_SEM(api, NH_COMMAND_TIMEOUT_MSEC);
     if (ret != NH_RET_SUCCESS) return ret;
 
@@ -180,7 +180,7 @@ nh_ret_t nh_ctrl_api_connect_ap(nh_ctrl_api_t *api, nh_ctrl_ap_conn_params_t *pa
                                 nh_ctrl_ap_conn_result_t *result) {
     nh_ret_t ret = NH_RET_SUCCESS;
 
-    NH_CTRL_API_CREATE_ALLOCATOR(c_alloc);
+    NH_CTRL_API_CREATE_ALLOCATOR(c_alloc, api);
     ret = NH_CTRL_API_TAKE_SEM(api, NH_COMMAND_TIMEOUT_MSEC);
     if (ret != NH_RET_SUCCESS) return ret;
 
@@ -262,7 +262,7 @@ void nh_ctrl_api_task(nh_ctrl_api_t *api) {
 }
 
 static nh_ret_t nh_ctrl_api_parse_event(nh_ctrl_api_t *api, CtrlMsgId *event_id, uint8_t *buf, uint32_t buf_len) {
-    NH_CTRL_API_CREATE_ALLOCATOR(c_alloc);
+    NH_CTRL_API_CREATE_ALLOCATOR(c_alloc, api);
 
     CtrlMsg *msg = ctrl_msg__unpack(&c_alloc, buf_len, buf);
     if (msg == NULL) {