diff --git a/include/dto/comm_big_data_test.h b/include/dto/comm_big_data_test.h
index 117dadd..c3a2a20 100644
--- a/include/dto/comm_big_data_test.h
+++ b/include/dto/comm_big_data_test.h
@@ -2,13 +2,13 @@
 #define COMM_BIG_DATA_TEST_H  
 #include <cstdint>
 #include "../enum/icd_id.h"
-#define MAX_BIG_DATA_SIZE (1024 * 1024)
+#define MAX_SIZE (900 * 1024)  // 900KB
 #pragma pack(push, 1)
 struct CommBigDataTest {
   IcdId message_id;
   uint32_t counter;
+  uint8_t big_data[MAX_SIZE];
   uint32_t big_data_size;
-  uint8_t big_data[MAX_BIG_DATA_SIZE];
 };
 #pragma pack(pop)
-#endif // COMM_BIG_DATA_TEST_H
+#endif // COMM_BIG_DATA_TEST_H
\ No newline at end of file