diff --git a/inc/util/cjson/cJSON.h b/inc/util/cjson/cJSON.h
index 57abda73..94f70ebc 100644
--- a/inc/util/cjson/cJSON.h
+++ b/inc/util/cjson/cJSON.h
@@ -52,8 +52,13 @@ then using the CJSON_API_VISIBILITY flag to "export" the same symbols the way CJ
 
 */
 
+#if defined(_M_IX86)
 #define CJSON_CDECL __cdecl
 #define CJSON_STDCALL __stdcall
+#else
+#define CJSON_CDECL
+#define CJSON_STDCALL
+#endif
 
 /* export symbols by default, this is necessary for copy pasting the C and header file */
 #if !defined(CJSON_HIDE_SYMBOLS) && !defined(CJSON_IMPORT_SYMBOLS) && !defined(CJSON_EXPORT_SYMBOLS)