diff --git a/include/stdio.h b/include/stdio.h
index 8446d63349f4..f8af8e2e2941 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -394,7 +394,7 @@ int	 asprintf(char **, const char *, ...) __printflike(2, 3);
 char	*ctermid_r(char *);
 void	 fcloseall(void);
 char	*fgetln(FILE *, size_t *);
-__const char *fmtcheck(const char *, const char *) __format_arg(2);
+const char *fmtcheck(const char *, const char *) __format_arg(2);
 int	 fpurge(FILE *);
 void	 setbuffer(FILE *, char *, int);
 int	 setlinebuf(FILE *);