--- Makefile.orig	2026-04-06 21:46:01 UTC
+++ Makefile
@@ -2,7 +2,7 @@ OS=posix
 .PHONY: all install clean
 
 OS=posix
-PREFIX=/usr/local
+PREFIX?=/usr/local
 BINDIR=$(PREFIX)/bin
 MANDIR=$(PREFIX)/share/man
 ALL_CFLAGS=$(CFLAGS) -std=c99 -Wall -Wextra -Wshadow -Wmissing-prototypes -Wpedantic -Wno-unused-parameter