diff --git a/cpp/json_parser.h b/cpp/json_parser.h
index b181c300a9..3505329660 100644
--- a/cpp/json_parser.h
+++ b/cpp/json_parser.h
@@ -2,9 +2,7 @@
 #define MLC_LLM_CPP_JSON_PARSER_H_
 
 #define PICOJSON_USE_INT64
-#ifndef __STDC_FORMAT_MACROS
 #define __STDC_FORMAT_MACROS
-#endif
 
 #include <picojson.h>
 #include <tvm/runtime/container/shape_tuple.h>