--- EMULib/Rules.gcc.orig	2014-01-31 00:39:34.000000000 +0700
+++ EMULib/Rules.gcc	2014-01-31 00:40:38.000000000 +0700
@@ -6,12 +6,12 @@
 LIBGBZ	= $(BASEDIR)/GBZ80
 PRIVATE	= $(BASEDIR)/Private
 
-CXX	= g++
-CC	= gcc
-CPP	= cpp
+CXX	?= g++
+CC	?= gcc
+CPP	?= cpp
 MOC	= moc
 SDT2GAS	= perl $(EMULIB)/Tools/sdt2gas.pl
-CFLAGS	= -O2 -pthread -I. -I.. -I$(EMULIB)
+CFLAGS	+= -pthread -I. -I.. -I$(EMULIB)
 DEFINES = -DZLIB
 LIBS    = -lz -lpthread