diff --git a/src/lib.rs b/src/lib.rs
index 91ed653d..e9cfafc8 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,18 @@
+// Copyright (C) 2018-2099 The crate authors.
+//
+// This program is free software: you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by the
+// Free Software Foundation, either version 3 of the License, or (at your
+// option) any later version.
+//
+// This program 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 General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
 #![feature(once_cell)]
 
 mod args;
diff --git a/src/logger.rs b/src/logger.rs
index d90efebd..4fe936d0 100644
--- a/src/logger.rs
+++ b/src/logger.rs
@@ -1,3 +1,18 @@
+// Copyright (C) 2018-2099 The crate authors.
+//
+// This program is free software: you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by the
+// Free Software Foundation, either version 3 of the License, or (at your
+// option) any later version.
+//
+// This program 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 General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
 use chrono::{DateTime, TimeZone, Utc};
 use nom;
 use nom::{
diff --git a/src/theming.rs b/src/theming.rs
index 198546a5..433b05c0 100644
--- a/src/theming.rs
+++ b/src/theming.rs
@@ -1,3 +1,18 @@
+// Copyright (C) 2018-2099 The crate authors.
+//
+// This program is free software: you can redistribute it and/or modify it
+// under the terms of the GNU General Public License as published by the
+// Free Software Foundation, either version 3 of the License, or (at your
+// option) any later version.
+//
+// This program 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 General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
 use enum_set::{CLike, EnumSet};
 use ncurses::{
     attr_t, init_pair, A_BLINK, A_BOLD, A_ITALIC, A_REVERSE, A_UNDERLINE, COLORS, COLOR_PAIR,