-OCAMLC = OCAMLPATH="$(METADIR)" ocamlfind ocamlc $(COMMONOPTS)
-OCAMLOPT = OCAMLPATH="$(METADIR)" ocamlfind ocamlopt $(COMMONOPTS)
+OCAMLC = OCAMLPATH="$(METADIR)" ocamlfind ocamlc -thread $(COMMONOPTS)
+OCAMLOPT = OCAMLPATH="$(METADIR)" ocamlfind ocamlopt -thread $(COMMONOPTS)