diff --git a/include/dix-config.h.in b/include/dix-config.h.in
index 78c2010d0..76f45f535 100644
--- a/include/dix-config.h.in
+++ b/include/dix-config.h.in
@@ -391,9 +391,15 @@
 /* Vendor name */
 #undef XVENDORNAME
 
+/* Number of bits in a file offset, on hosts where this is settable. */
+#undef _FILE_OFFSET_BITS
+
 /* Enable GNU and other extensions to the C environment for GLIBC */
 #undef _GNU_SOURCE
 
+/* Define for large files, on AIX-style hosts. */
+#undef _LARGE_FILES
+
 /* Define to empty if `const' does not conform to ANSI C. */
 #undef const