-LIBDIVECOMPUTERDIR = /usr/local
-LIBDIVECOMPUTERINCLUDES = $(LIBDIVECOMPUTERDIR)/include/libdivecomputer
-LIBDIVECOMPUTERARCHIVE = $(LIBDIVECOMPUTERDIR)/lib/libdivecomputer.a
+ifneq ($(strip $(libdc-local)),)
+ LIBDIVECOMPUTERDIR = /usr/local
+ LIBDIVECOMPUTERINCLUDES = $(LIBDIVECOMPUTERDIR)/include/libdivecomputer
+ LIBDIVECOMPUTERARCHIVE = -L$(LIBDIVECOMPUTERDIR)/lib -ldivecomputer
+else ifneq ($(strip $(libdc-usr)),)
+ LIBDIVECOMPUTERDIR = /usr
+ LIBDIVECOMPUTERINCLUDES = $(LIBDIVECOMPUTERDIR)/include/libdivecomputer
+ LIBDIVECOMPUTERARCHIVE = -ldivecomputer
+else
+ $(error Cannot find libdivecomputer - please edit Makefile)
+endif