diff --git a/sing_macros/src/keyword.rs b/sing_macros/src/keyword.rs
index 6724b4c..a2d0584 100644
--- a/sing_macros/src/keyword.rs
+++ b/sing_macros/src/keyword.rs
@@ -1,3 +1,20 @@
+// Copyright 2022 Daniel Mowitz
+//
+// This file is part of sing.
+//
+// sing 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.
+//
+// sing 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 Affero General Public License for more details.
+// 
+// You should have received a copy of the GNU Affero General Public License
+//  along with sing. If not, see <https://www.gnu.org/licenses/>. 
+
 use syn::custom_keyword;
 
 custom_keyword!(ioe);