--- a/Makefile
+++ b/Makefile
@@ -37,8 +37,8 @@ OPT_PLUS=-O3 $(NATIVE)
 
 DEFINE=-D_REENTRANT
 
-CFLAGS=-pipe $(WARN) $(DEFINE) $(OPT_REG)
-CFLAGS_OPT=-pipe $(WARN) $(DEFINE) $(OPT_PLUS)
+CFLAGS+=-pipe $(WARN) $(DEFINE) $(OPT_REG)
+CFLAGS_OPT+=-pipe $(WARN) $(DEFINE) $(OPT_PLUS)
 
 #CFLAGS=-pipe -Os -march=pentiumpro -mcpu=pentiumpro -fomit-frame-pointer -fschedule-insns2 -Wall
 
