--- Makefile.orig	2016-12-20 00:05:06.000000000 +0900
+++ Makefile	2017-11-18 08:20:31.000000000 +0900
@@ -15,8 +15,6 @@
 RELEASE := $(shell bin/get_version.sh --release)
 FULL    := $(shell bin/get_version.sh --full)
 
-PREFIX  := /usr/local
-
 CFG_DIR := $(PREFIX)/etc
 BIN_DIR := $(PREFIX)/bin
 MAN_DIR := $(PREFIX)/share/man