AC_HEADER_DIRENT
AC_HEADER_STDC
# elf_hp.h is for HP/UX 64-bit shared library support.
-AC_CHECK_HEADERS([nlist.h machine/reg.h poll.h sys/poll.h proc_service.h \
+AC_CHECK_HEADERS([nlist.h machine/reg.h poll.h sys/poll.h sys/socket.h proc_service.h \
thread_db.h signal.h stddef.h \
stdlib.h string.h memory.h strings.h sys/fault.h \
sys/file.h sys/filio.h sys/ioctl.h sys/param.h \