diff --git a/osbase/gpt/gpt.go b/osbase/gpt/gpt.go
index 126021b..3d3cadb 100644
--- a/osbase/gpt/gpt.go
+++ b/osbase/gpt/gpt.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 // Package gpt implements reading and writing GUID Partition Tables as specified
 // in the UEFI Specification. It only implements up to 128 partitions per table
 // (same as most other implementations) as more would require a dynamic table
diff --git a/osbase/gpt/gpt_test.go b/osbase/gpt/gpt_test.go
index 8e63a58..0174266 100644
--- a/osbase/gpt/gpt_test.go
+++ b/osbase/gpt/gpt_test.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package gpt
 
 import (
diff --git a/osbase/gpt/linux_test.go b/osbase/gpt/linux_test.go
index 030c8eb..decf5ec 100644
--- a/osbase/gpt/linux_test.go
+++ b/osbase/gpt/linux_test.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package gpt
 
 import (
diff --git a/osbase/gpt/mbr.go b/osbase/gpt/mbr.go
index fa82359..0489afc 100644
--- a/osbase/gpt/mbr.go
+++ b/osbase/gpt/mbr.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package gpt
 
 import (
diff --git a/osbase/gpt/mbr_test.go b/osbase/gpt/mbr_test.go
index 2ed4ed1..dd9ef48 100644
--- a/osbase/gpt/mbr_test.go
+++ b/osbase/gpt/mbr_test.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package gpt
 
 import "testing"
diff --git a/osbase/gpt/structs_test.go b/osbase/gpt/structs_test.go
index dc53635..5b612ac 100644
--- a/osbase/gpt/structs_test.go
+++ b/osbase/gpt/structs_test.go
@@ -1,3 +1,6 @@
+// Copyright The Monogon Project Authors.
+// SPDX-License-Identifier: Apache-2.0
+
 package gpt
 
 import (