After compiling the vanilla 3.35.2 Tcl binding, I modified the makefile.vc to include the new math functions, and that went well. Then I added ICU, and got an error: ..\..\sqlite3.c(197501): fatal error C1083: Cannot open include file: 'unicode/utypes.h': No such file or directory What am I doing wrong? I used magicsplat for the Tcl stubs. Gerry Snyder