diff --git a/src/components.rs b/src/components.rs
index ad6ad0a..78f2851 100644
--- a/src/components.rs
+++ b/src/components.rs
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 use std::{
     collections::HashMap,
     fs::{File, OpenOptions},
diff --git a/src/disk.rs b/src/disk.rs
index 9e1752c..529eae7 100644
--- a/src/disk.rs
+++ b/src/disk.rs
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 use std::io::{Read, Write};
 use std::{fs::File, path::Path};
 
diff --git a/src/main.rs b/src/main.rs
index 2e3252c..3c21969 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 use std::collections::HashMap;
 use std::error;
 use std::fmt;