diff --git a/src/btc.rs b/src/btc.rs
index 02cbd20..838503f 100644
--- a/src/btc.rs
+++ b/src/btc.rs
@@ -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 https://mozilla.org/MPL/2.0/.
+
 use std::fs::File;
 use std::time::Duration;
 use ast::{Defs, Def, Expr};
diff --git a/src/currency.rs b/src/currency.rs
index a048ce5..ba4f037 100644
--- a/src/currency.rs
+++ b/src/currency.rs
@@ -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 https://mozilla.org/MPL/2.0/.
+
 use std::fs::File;
 use std::time::Duration;
 use xml::EventReader;