-OCAMLOPTIONS = -package "$(REQUIRES)" -predicates "$(PREDICATES)" -thread
-OCAMLFIND = OCAMLPATH=../../components/METAS/ ocamlfind
+OCAMLOPTIONS = -package "$(REQUIRES)" -predicates "$(PREDICATES)" -thread -rectypes
+ifeq ($(origin OCAMLPATH), undefined)
+OCAMLFIND = OCAMLPATH=../../components/METAS ocamlfind
+else
+OCAMLFIND = ocamlfind
+endif