diff --git a/src/main.rs b/src/main.rs
index d09d763..fc0114e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,17 @@
+/*
+    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 gio::prelude::*;
 
diff --git a/src/port_util.rs b/src/port_util.rs
index 51abeb3..0faf29c 100644
--- a/src/port_util.rs
+++ b/src/port_util.rs
@@ -1,3 +1,21 @@
+/*
+    This file is part of Tarangam.
+
+    Tarangam 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.
+
+    Tarangam 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 Tarangam.  If not, see <https://www.gnu.org/licenses/>
+*/
+
+//! Feel free to see through codes. Application is not written to be used as a library for other app. :)
 
 use gtk::prelude::*;
 
diff --git a/src/util.rs b/src/util.rs
index 7f23cb6..5b2f782 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -1,3 +1,21 @@
+/*
+    This file is part of Tarangam.
+
+    Tarangam 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.
+
+    Tarangam 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 Tarangam.  If not, see <https://www.gnu.org/licenses/>
+*/
+
+//! Feel free to see through codes. Application is not written to be used as a library for other app. :)
 
 use std::sync::{atomic::*, Mutex};