diff --git a/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_VOID_P.h b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_VOID_P.h
new file mode 100644
index 0000000..7c543af
--- /dev/null
+++ b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_VOID_P.h
@@ -0,0 +1,9 @@
+// SIZEOF_VOID_P
+
+#undef SIZEOF_VOID_P
+
+#if defined(_WIN64) || defined(__x86_64__) || defined(__ppc64__)
+#  define SIZEOF_VOID_P 8
+#else
+#  define SIZEOF_VOID_P 4
+#endif