diff --git a/libbuild2-autoconf/libbuild2/autoconf/checks/HAVE_SA_FAMILY_T.h b/libbuild2-autoconf/libbuild2/autoconf/checks/HAVE_SA_FAMILY_T.h
new file mode 100644
index 0000000..4ff55a0
--- /dev/null
+++ b/libbuild2-autoconf/libbuild2/autoconf/checks/HAVE_SA_FAMILY_T.h
@@ -0,0 +1,18 @@
+// HAVE_SA_FAMILY_T : BUILD2_AUTOCONF_LIBC_VERSION
+
+#ifndef BUILD2_AUTOCONF_LIBC_VERSION
+#  error BUILD2_AUTOCONF_LIBC_VERSION appears to be conditionally included
+#endif
+
+#undef HAVE_SA_FAMILY_T
+
+/* Since Linux/glibc 2.1, OpenBSD >=2.7, FreeBSD >=4.0, NetBSD >=1.5, Mac OS X 10.0
+ * NOTE: POSIX.1g (2000) specifies this type name for the 'sa_family' member.
+ */
+#if BUILD2_AUTOCONF_GLIBC_PREREQ(2, 1)      || \
+    BUILD2_AUTOCONF_OPENBSD_PREREQ(200015)  || \
+    BUILD2_AUTOCONF_FREEBSD_PREREQ(4, 0)    || \
+    BUILD2_AUTOCONF_NETBSD_PREREQ(1, 5)     || \
+    BUILD2_AUTOCONF_MACOS_PREREQ(10, 0)
+#  define HAVE_SA_FAMILY_T 1
+#endif