diff --git a/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_INT.h b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_INT.h
new file mode 100644
index 0000000..371185b
--- /dev/null
+++ b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_INT.h
@@ -0,0 +1,16 @@
+// SIZEOF_INT
+
+#undef SIZEOF_INT
+
+#ifdef _MSC_VER
+#  define SIZEOF_INT 4
+#else
+/* Both GCC and Clang (and maybe others) define __SIZEOF_INT__. */
+#  ifdef __SIZEOF_INT__
+#    define SIZEOF_INT __SIZEOF_INT__
+#  endif
+#endif
+
+#ifndef SIZEOF_INT
+#  error unable to determine size of int
+#endif
diff --git a/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_LONG_LONG.h b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_LONG_LONG.h
new file mode 100644
index 0000000..7729bb5
--- /dev/null
+++ b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_LONG_LONG.h
@@ -0,0 +1,16 @@
+// SIZEOF_LONG_LONG
+
+#undef SIZEOF_LONG_LONG
+
+#ifdef _MSC_VER
+#  define SIZEOF_LONG_LONG 8
+#else
+/* Both GCC and Clang (and maybe others) define __SIZEOF_LONG_LONG__. */
+#  ifdef __SIZEOF_LONG_LONG__
+#    define SIZEOF_LONG_LONG __SIZEOF_LONG_LONG__
+#  endif
+#endif
+
+#ifndef SIZEOF_LONG_LONG
+#  error unable to determine size of long long
+#endif
diff --git a/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_PTHREAD_T.h b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_PTHREAD_T.h
new file mode 100644
index 0000000..9ad79d1
--- /dev/null
+++ b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_PTHREAD_T.h
@@ -0,0 +1,15 @@
+// SIZEOF_PTHREAD_T
+
+#undef SIZEOF_PTHREAD_T
+
+#ifndef _WIN32
+#   ifdef defined(__APPLE__)
+#       ifdef __LP64__
+#           define SIZEOF_PTHREAD_T 8
+#       else
+#           define SIZEOF_PTHREAD_T 4
+#       endif
+#   else
+#       define SIZEOF_PTHREAD_T 4
+#   endif
+#endif
diff --git a/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_SHORT.h b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_SHORT.h
new file mode 100644
index 0000000..b411aa2
--- /dev/null
+++ b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_SHORT.h
@@ -0,0 +1,16 @@
+// SIZEOF_SHORT
+
+#undef SIZEOF_SHORT
+
+#ifdef _MSC_VER
+#  define SIZEOF_SHORT 2
+#else
+/* Both GCC and Clang (and maybe others) define __SIZEOF_SHORT__. */
+#  ifdef __SIZEOF_SHORT__
+#    define SIZEOF_SHORT __SIZEOF_SHORT__
+#  endif
+#endif
+
+#ifndef SIZEOF_SHORT
+#  error unable to determine size of short
+#endif