-AC_CHECK_FUNCS([mlockall strnlen getloadavg statvfs getmntent_r])
-AC_CHECK_HEADERS([mntent.h sys/statvfs.h linux/types.h linux/if_ether.h stdatomic.h])
+AC_CHECK_MEMBERS([struct mmsghdr.msg_len], [], [], [[#include <sys/socket.h>]])
+AC_CHECK_MEMBERS([struct sockaddr_in6.sin6_scope_id], [], [],
+ [[#include <sys/socket.h>
+#include <sys/types.h>
+#include <netinet/in.h>]])
+AC_CHECK_FUNCS([mlockall strnlen getloadavg statvfs getmntent_r sendmmsg clock_gettime])
+AC_CHECK_HEADERS([mntent.h sys/statvfs.h linux/types.h linux/if_ether.h])
+AC_CHECK_HEADERS([linux/net_namespace.h stdatomic.h bits/floatn-common.h])