diff --git a/gcc/sys-protos.h b/gcc/sys-protos.h
index 303538e8119..bf094f976e7 100644
--- a/gcc/sys-protos.h
+++ b/gcc/sys-protos.h
@@ -858,7 +858,7 @@ extern int                    raise(int);
 extern int                    rand(void);
 extern long                   random(void);
 extern int                    raw(void);
-extern int                    read(int, void *, unsigned int);
+extern int                    read(int, void *, size_t);
 extern struct dirent *        readdir(DIR *);
 extern int                    readlink(const char *, void *, int);
 extern void *                 realloc(void *, size_t);
@@ -1264,7 +1264,7 @@ extern int                    wnoutrefresh(WINDOW *);
 extern int                    wprintw(WINDOW *, ...);
 extern int                    wredrawln(WINDOW *, int, int);
 extern int                    wrefresh(WINDOW *);
-extern int                    write(int, const void *, unsigned int);
+extern int                    write(int, const void *, size_t);
 extern int                    wscanw(WINDOW *, ...);
 extern int                    wscrl(WINDOW *, int);
 extern int                    wsetscrreg(WINDOW *, int, int);