diff --git a/configure.in b/configure.in
index 97acf325ae55d0091ce65e026722fc8248656b3d..7487fc9a8c7d29e89d0e2b1c68c4293715e30bba 100644
--- a/configure.in
+++ b/configure.in
@@ -470,6 +470,13 @@ dnl ** check for leading underscores in symbol names
 #
 AC_UNDERSCORE
 
+#
+dnl ** check the size of various C types
+#
+AC_CHECK_SIZEOF(int,    4)
+AC_CHECK_SIZEOF(long,   4)
+AC_CHECK_SIZEOF(void *, 4)
+
 AC_OUTPUT(mk/config.mk, echo timestamp > mk/stamp-h )
 
 echo ''
diff --git a/mk/config.h.in b/mk/config.h.in
index 0596c444ceb0dd5627f8691ec9e089c3e81e6ec4..6eac388a4bcfcdf5b9da272671a66ef38cf4a8a2 100644
--- a/mk/config.h.in
+++ b/mk/config.h.in
@@ -188,3 +188,12 @@
 
 /* Define this if your time.h defines altzone */
 #undef HAVE_ALTZONE
+
+/* sizeof(int) */
+#undef SIZEOF_INT
+
+/* sizeof(long) */
+#undef SIZEOF_LONG
+
+/* sizeof(void *) */
+#undef SIZEOF_VOID_P