diff --git a/tld.go b/tld.go
index 1e8a775..f107844 100644
--- a/tld.go
+++ b/tld.go
@@ -1,3 +1,9 @@
+// Copyright 2020 Walter Scheper <walter.scheper@gmail.com>
+//
+// 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 https://mozilla.org/MPL/2.0/.
+
 package rapid
 
 import "strings"
diff --git a/url.go b/url.go
index 4dba2ff..beab283 100644
--- a/url.go
+++ b/url.go
@@ -1,3 +1,9 @@
+// Copyright 2020 Walter Scheper <walter.scheper@gmail.com>
+//
+// 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 https://mozilla.org/MPL/2.0/.
+
 package rapid
 
 import (
diff --git a/url_example_test.go b/url_example_test.go
index aba6a6a..cf1da6a 100644
--- a/url_example_test.go
+++ b/url_example_test.go
@@ -1,3 +1,9 @@
+// Copyright 2020 Walter Scheper <walter.scheper@gmail.com>
+//
+// 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 https://mozilla.org/MPL/2.0/.
+
 package rapid_test
 
 import (
diff --git a/url_external_test.go b/url_external_test.go
index 26fa70d..1832e73 100644
--- a/url_external_test.go
+++ b/url_external_test.go
@@ -1,3 +1,9 @@
+// Copyright 2020 Walter Scheper <walter.scheper@gmail.com>
+//
+// 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 https://mozilla.org/MPL/2.0/.
+
 package rapid_test
 
 import (