diff --git a/src/opml2list.xml b/src/opml2list.xml
index 53f9371..c3217b9 100644
--- a/src/opml2list.xml
+++ b/src/opml2list.xml
@@ -1,4 +1,24 @@
 <?xml version="1.0" encoding="UTF-8"?>
+
+<!---
+Copyright (c) 2021 Daniel Mowitz <xslfeed.daniel@mowitz.rocks>
+
+This file is part of xslfeed.
+
+xslfeed is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published
+by the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+xslfeed is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with xslfeed.  If not, see <https://www.gnu.org/licenses/>.
+--->
+
 <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output method="text" />