--- a/Makefile
+++ b/Makefile
@@ -7,8 +7,7 @@
 
 rebuild: clean delete cosmomc
 
-cosmomc: BUILD ?= MPI
-cosmomc_debug: BUILD ?= MPI
+BUILD ?= MPI
 
 getdist: ./source/*.*90
 	cd ./source && make getdist BUILD=$(BUILD)
--- a/source/Makefile
+++ b/source/Makefile
@@ -57,11 +57,7 @@
 #commented above is (I think) for Mac; this is standard linux (sudo apt-get install liblapack-dev)
 LAPACKL = -lblas -llapack
 
-#march native does not work on Mac, otherwise use (comment out if your cluster is inhomogeneous)
-ifneq ($(shell uname -s),Darwin)
-#native optimization does not work on Mac
 FFLAGS+=-march=native
-endif
 
 endif