diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3339f36..c9f4084 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,7 @@
 # 1.3.0
 * 英訳の追加
+* GNU Make → BSD Make
+* GPLv2 → ISC
 
 # 1.2.0
 * やっとTOTP機能性を修正した
diff --git a/LICENSE.txt b/LICENSE.txt
index e69de29..c4d9131 100644
--- a/LICENSE.txt
+++ b/LICENSE.txt
@@ -0,0 +1,14 @@
+Copyright © 2004-2011 by Internet Systems Consortium, Inc. ("ISC")
+Copyright © 2018-2024 by 076.moe
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD
+TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
+CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+SOFTWARE.
diff --git a/Makefile b/Makefile
index b6f30ff..0f9269d 100644
--- a/Makefile
+++ b/Makefile
@@ -1,19 +1,19 @@
-UNAME_S := $(shell uname -s)
+UNAME_S!=uname -s
 
-NAME := $(shell cat main.c | grep "const char\* sofname" | awk '{print $$5}' | sed "s/\"//g" | sed "s/;//" )
-VERSION := $(shell cat main.c | grep "const char\* version" | awk '{print $$5}' | sed "s/\"//g" | sed "s/;//" )
+NAME!=cat main.c | grep "const char\* sofname" | awk '{print $$5}' | sed "s/\"//g" | sed "s/;//"
+VERSION!=cat main.c | grep "const char\* version" | awk '{print $$5}' | sed "s/\"//g" | sed "s/;//"
+PREFIX=/usr/local
+
+.if ${UNAME_S} == "FreeBSD"
+MANPREFIX=${PREFIX}/share/man
+.elif ${UNAME_S} == "Linux"
 PREFIX=/usr
 MANPREFIX=${PREFIX}/share/man
-ifeq ($(UNAME_S),FreeBSD)
-	PREFIX=/usr/local
-endif
-ifeq ($(UNAME_S),OpenBSD)
-	PREFIX=/usr/local
-	MANPREFIX=${PREFIX}/man
-endif
-ifeq ($(UNAME_S),NetBSD)
-	PREFIX=/usr/pkg
-endif
+.elif ${UNAME_S} == "NetBSD"
+PREFIX=/usr/pkg
+MANPREFIX=${PREFIX}/share/man
+.endif
+
 CC=cc
 FILES=main.c showpass.c yankpass.c addpass.c delpass.c listpass.c genpass.c initpass.c otppass.c base32.c
 CFLAGS=-Wall -Wextra -O3 -I${PREFIX}/include -L${PREFIX}/lib