diff --git a/mlibc/include/stdio.h b/mlibc/include/stdio.h
index 811e2165..53154d11 100644
--- a/mlibc/include/stdio.h
+++ b/mlibc/include/stdio.h
@@ -99,6 +99,7 @@ int eputs (char const* s);
 int fprintf (FILE *stream, char const *format, ...);
 int fputc (int c, int fd);
 int fputs (char const* s, int fd);
+size_t fwrite (void const *ptr, size_t size, size_t nmemb, FILE *stream);
 int getchar ();
 int printf (char const* format, ...);
 int putchar (int c);
diff --git a/mlibc/libc-mes+tcc.c b/mlibc/libc-mes+tcc.c
index d18fb88e..9032ca06 100644
--- a/mlibc/libc-mes+tcc.c
+++ b/mlibc/libc-mes+tcc.c
@@ -49,6 +49,12 @@ fprintf (FILE *stream, char const *format, ...)
   return 0;
 }
 
+size_t
+fwrite (void const *ptr, size_t size, size_t nmemb, FILE *stream)
+{
+  return 0;
+}
+
 struct tm *
 localtime (time_t const *timep)
 {