--- extern/btyacc/Makefile	2013-10-03 02:19:05.000000000 -0500
+++ extern/btyacc/Makefile	2013-10-03 02:19:21.000000000 -0500
@@ -8,14 +8,14 @@
 
 HDRS	      = defs.h mstring.h
 
-CFLAGS	      = -g -Wall -Wstrict-prototypes -Wmissing-prototypes
+CFLAGS	      += -g -Wall -Wstrict-prototypes -Wmissing-prototypes
 
 #LDFLAGS	      = -static
 
 LIBS	      =
 
-CC	      = gcc
-LINKER	      = gcc
+CC	      ?= gcc
+LINKER	      ?= gcc
 # LINKER      = cl
 # CC	      = cl