diff --git a/mps/code/w3gen.def b/mps/code/w3gen.def
index 8f3927bb816..d9ebcf013e0 100644
--- a/mps/code/w3gen.def
+++ b/mps/code/w3gen.def
@@ -1,5 +1,5 @@
 ; $Header$
-; DO NOT EDIT.  Automatically generated by !Header: //info.ravenbrook.com/project/mps/branch/2004-12-15/dll/code/expgen.sh#1 !
+; DO NOT EDIT.  Automatically generated by !Header: //info.ravenbrook.com/project/mps/branch/2004-12-15/dll/code/expgen.sh#4 !
 EXPORTS
 ; mps.h
 mps_ap_fill_with_reservoir_permit
@@ -133,6 +133,8 @@ mps_mv_free_size
 mps_class_mv
 ; mpscsnc.h
 mps_class_snc
+; mpslibcb.h
+mps_lib_callback_register
 ; mpstd.h
 ; mpsw3.h - by hand
 mps_SEH_filter