--- Makefile	2024-05-18 12:43:06.000000000 +0800
+++ Makefile	2024-12-18 20:48:21.000000000 +0800
@@ -33,7 +33,7 @@
 version = $(shell cat .version 2>/dev/null || git describe --tags HEAD 2>/dev/null | sed s/^v// || echo unknown)
 version != cat .version 2>/dev/null || ( git describe --tags HEAD 2>/dev/null | sed s/^v// ) || echo unknown
 
-PREFIX = /usr/local
+PREFIX ?= /usr/local
 DESTDIR = # root dir
 
 bindir = $(DESTDIR)$(PREFIX)/bin