diff --git a/stdborg.py b/stdborg.py
index 4a23470..81143bb 100644
--- a/stdborg.py
+++ b/stdborg.py
@@ -1,3 +1,7 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
 import logging
 
 from uniborg import Uniborg
diff --git a/stdplugins/testplugin.py b/stdplugins/testplugin.py
index 5635119..a7e8189 100644
--- a/stdplugins/testplugin.py
+++ b/stdplugins/testplugin.py
@@ -1,3 +1,7 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
 from telethon import events
 
 @borg.on(events.NewMessage)
diff --git a/uniborg/_core.py b/uniborg/_core.py
index e69de29..5501cd4 100644
--- a/uniborg/_core.py
+++ b/uniborg/_core.py
@@ -0,0 +1,4 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+