--- daligner.orig/Makefile
+++ daligner/Makefile
@@ -1,4 +1,4 @@
-CFLAGS = -O3 -Wall -Wextra -fno-strict-aliasing
+CFLAGS += -O3 -Wall -Wextra -fno-strict-aliasing
 
 ALL = daligner HPCdaligner HPCmapper LAsort LAmerge LAsplit LAcat LAshow LAcheck
 
