-OBJS += virt_top_calendar.cmo
-OCAMLCPACKAGES := $(OCAMLCPACKAGES),calendar
+OBJS += virt_top_calendar1.cmo
+OCAMLCPACKAGES += -package calendar
+endif
+ifneq ($(pkg_calendar2),no)
+OBJS += virt_top_calendar2.cmo
+OCAMLCPACKAGES += -package calendar