diff --git a/include/stdio.h b/include/stdio.h
index 813e1ac6b..04725d244 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -84,9 +84,9 @@ FILE* __fastcall__ fopen (const char* name, const char* mode);
 int fprintf (FILE* f, const char* format, ...);
 int fputc (int c, FILE* f);
 int fputs (const char* s, FILE* f);
-size_t fread (void* buf, size_t size, size_t count, FILE* f);
+size_t __fastcall__ fread (void* buf, size_t size, size_t count, FILE* f);
 FILE* freopen (const char* name, const char* mode, FILE* f);
-size_t fwrite (const void* buf, size_t size, size_t count, FILE* f);
+size_t __fastcall__ fwrite (const void* buf, size_t size, size_t count, FILE* f);
 int fgetpos(FILE* f, fpos_t *pos);
 int fsetpos(FILE* f, const fpos_t* pos);
 long ftell(FILE* f);