Hi, > More generally speaking, given the way Windows DLLs work, I > don't think it is possible at all to put Caml-C stub code in > a DLL and pass that DLL to ocamlopt. Static linking is your > friend here. This solves my problem. The correct compile.sh is attached. Thank you all for the answers! Christoph Bauer #!/bin/sh -v gcc -mno-cygwin -c -O -mms-bitfields -UCAML_DLL -I c:/ocamlmgw/lib test.c -g ar rcs libtest.a test.o ocamlopt -o test_it.exe test_it.ml -cclib "-L. -ltest"