AC_HEADER_SYS_WAIT
AC_TYPE_OFF_T
AC_TYPE_UID_T
-AC_CHECK_FUNCS([atoll stat64 strnlen mremap setrlimit sysconf initgroups strndup gethostbyname2 getpeerucred getpeereid setresuid $funcstocheck getifaddrs freeifaddrs])
+AC_CHECK_FUNCS([atoll stat64 strnlen mremap setrlimit sysconf initgroups strndup gethostbyname2 getpeerucred getpeereid setresuid $funcstocheck getifaddrs freeifaddrs getresgid])
# restore LIBS
LIBS=$SAVE_LIBS