--- Makefile.orig	2014-08-15 15:40:43.000000000 -0400
+++ Makefile	2014-08-15 15:41:37.000000000 -0400
@@ -1,5 +1,5 @@
-CC=gcc
-CFLAGS=-Wall -pedantic -g -DUNIX_HOST
+CC?=gcc
+CFLAGS+=-Wall -pedantic -g -DUNIX_HOST
 LIBS=-lm -lreadline
 
 TARGET	= picoc
@@ -14,7 +14,7 @@
 all: $(TARGET)
 
 $(TARGET): $(OBJS)
-	$(CC) $(CFLAGS) -o $(TARGET) $(OBJS) $(LIBS)
+	$(CC) $(CFLAGS) ${CPPFLAGS} -o $(TARGET) $(OBJS) ${LDFLAGS} $(LIBS)
 
 test:	all
 	(cd tests; make test)