diff --git a/CHANGELOG.md b/CHANGELOG.md
index b0aca53..c9f4084 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +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.