--- mujs-0_p20150202/Makefile
+++ mujs-0_p20150202/Makefile
@@ -2,23 +2,17 @@
 HDRS := $(wildcard js*.h mujs.h utf.h regex.h)
 OBJS := $(SRCS:%.c=build/%.o)
 
-prefix ?= /usr/local
+prefix ?= /usr
 bindir ?= $(prefix)/bin
 incdir ?= $(prefix)/include
 libdir ?= $(prefix)/lib
 
-CFLAGS := -std=c99 -pedantic -Wall -Wextra -Wno-unused-parameter
+CFLAGS += -std=c99 -pedantic -Wall -Wextra -Wno-unused-parameter
 
 ifeq "$(CC)" "clang"
 CFLAGS += -Wunreachable-code
 endif
 
-ifeq "$(build)" "debug"
-CFLAGS += -g
-else
-CFLAGS += -O2
-endif
-
 default: build build/mujs build/mujsone
 
 debug: