diff --git a/include/rest_rpc/const_vars.h b/include/rest_rpc/const_vars.h
index 2beb0db..cd98135 100644
--- a/include/rest_rpc/const_vars.h
+++ b/include/rest_rpc/const_vars.h
@@ -26,6 +26,7 @@ struct message_type {
 };
 
 static const uint8_t MAGIC_NUM = 39;
+#pragma pack(4)
 struct rpc_header {
   uint8_t magic;
   request_type req_type;
@@ -33,6 +34,7 @@ struct rpc_header {
   uint64_t req_id;
   uint32_t func_id;
 };
+#pragma pack()
 
 static const size_t MAX_BUF_LEN = 1048576 * 10;
 static const size_t HEAD_LEN = sizeof(rpc_header);