diff --git a/espanso-ui/src/icons.rs b/espanso-ui/src/icons.rs
index 5fea61e..b1adca0 100644
--- a/espanso-ui/src/icons.rs
+++ b/espanso-ui/src/icons.rs
@@ -1,3 +1,22 @@
+/*
+ * This file is part of espanso.
+ *
+ * Copyright (C) 2019-2021 Federico Terzi
+ *
+ * espanso 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.
+ *
+ * espanso 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 espanso.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum TrayIcon {
   Normal,
diff --git a/espanso-ui/src/lib.rs b/espanso-ui/src/lib.rs
index 0792975..07e9279 100644
--- a/espanso-ui/src/lib.rs
+++ b/espanso-ui/src/lib.rs
@@ -1,3 +1,22 @@
+/*
+ * This file is part of espanso.
+ *
+ * Copyright (C) 2019-2021 Federico Terzi
+ *
+ * espanso 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.
+ *
+ * espanso 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 espanso.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
 use anyhow::Result;
 use icons::TrayIcon;
 use thiserror::Error;
diff --git a/espanso-ui/src/linux/mod.rs b/espanso-ui/src/linux/mod.rs
index 3135019..cfdebbe 100644
--- a/espanso-ui/src/linux/mod.rs
+++ b/espanso-ui/src/linux/mod.rs
@@ -1,3 +1,22 @@
+/*
+ * This file is part of espanso.
+ *
+ * Copyright (C) 2019-2021 Federico Terzi
+ *
+ * espanso 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.
+ *
+ * espanso 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 espanso.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
 use anyhow::Result;
 use log::error;
 use notify_rust::Notification;