diff --git a/libbuild2-autoconf/libbuild2/autoconf/checks/HAVE_MACH_ABSOLUTE_TIME.h b/libbuild2-autoconf/libbuild2/autoconf/checks/HAVE_MACH_ABSOLUTE_TIME.h
new file mode 100644
index 0000000..bd31078
--- /dev/null
+++ b/libbuild2-autoconf/libbuild2/autoconf/checks/HAVE_MACH_ABSOLUTE_TIME.h
@@ -0,0 +1,13 @@
+// HAVE_MACH_ABSOLUTE_TIME : BUILD2_AUTOCONF_LIBC_VERSION
+
+#ifndef BUILD2_AUTOCONF_LIBC_VERSION
+#  error BUILD2_AUTOCONF_LIBC_VERSION appears to be conditionally included
+#endif
+
+#undef HAVE_MACH_ABSOLUTE_TIME
+
+/* Mac OS X 10.0
+ */
+#if BUILD2_AUTOCONF_MACOS_PREREQ(10, 0)
+#  define HAVE_MACH_ABSOLUTE_TIME 1
+#endif
diff --git a/libbuild2-autoconf/libbuild2/autoconf/checks/HAVE_MACH_MACH_H.h b/libbuild2-autoconf/libbuild2/autoconf/checks/HAVE_MACH_MACH_H.h
new file mode 100644
index 0000000..d2a2dc7
--- /dev/null
+++ b/libbuild2-autoconf/libbuild2/autoconf/checks/HAVE_MACH_MACH_H.h
@@ -0,0 +1,13 @@
+// HAVE_MACH_MACH_H : BUILD2_AUTOCONF_LIBC_VERSION
+
+#ifndef BUILD2_AUTOCONF_LIBC_VERSION
+#  error BUILD2_AUTOCONF_LIBC_VERSION appears to be conditionally included
+#endif
+
+#undef HAVE_MACH_MACH_H
+
+/* Mac OS X 10.0
+ */
+#if BUILD2_AUTOCONF_MACOS_PREREQ(10, 0)
+#  define HAVE_MACH_MACH_H 1
+#endif
diff --git a/libbuild2-autoconf/libbuild2/autoconf/checks/HAVE_MACH_MACH_TIME_H.h b/libbuild2-autoconf/libbuild2/autoconf/checks/HAVE_MACH_MACH_TIME_H.h
new file mode 100644
index 0000000..98d7f72
--- /dev/null
+++ b/libbuild2-autoconf/libbuild2/autoconf/checks/HAVE_MACH_MACH_TIME_H.h
@@ -0,0 +1,13 @@
+// HAVE_MACH_MACH_TIME_H : BUILD2_AUTOCONF_LIBC_VERSION
+
+#ifndef BUILD2_AUTOCONF_LIBC_VERSION
+#  error BUILD2_AUTOCONF_LIBC_VERSION appears to be conditionally included
+#endif
+
+#undef HAVE_MACH_MACH_TIME_H
+
+/* Mac OS X 10.0
+ */
+#if BUILD2_AUTOCONF_MACOS_PREREQ(10, 0)
+#  define HAVE_MACH_MACH_TIME_H 1
+#endif