diff --git a/plugin/auth.go b/plugin/auth.go
index adc834b..eb65e89 100644
--- a/plugin/auth.go
+++ b/plugin/auth.go
@@ -1,3 +1,6 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
 package plugin
 
 import (
diff --git a/plugin/client.go b/plugin/client.go
index 143e8dc..954df6a 100644
--- a/plugin/client.go
+++ b/plugin/client.go
@@ -1,3 +1,6 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
 package plugin
 
 import (
diff --git a/plugin/const.go b/plugin/const.go
index 3287e24..6c6533a 100644
--- a/plugin/const.go
+++ b/plugin/const.go
@@ -1,3 +1,6 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
 package plugin
 
 const (
diff --git a/plugin/option.go b/plugin/option.go
index 485b3f6..342e706 100644
--- a/plugin/option.go
+++ b/plugin/option.go
@@ -1,3 +1,6 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
 package plugin
 
 import (
diff --git a/plugin/plugin.go b/plugin/plugin.go
index d15d7a6..bca5f6f 100644
--- a/plugin/plugin.go
+++ b/plugin/plugin.go
@@ -1,3 +1,6 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
 package plugin
 
 import (
diff --git a/plugin/plugin_test.go b/plugin/plugin_test.go
index dc0b415..2a5f241 100644
--- a/plugin/plugin_test.go
+++ b/plugin/plugin_test.go
@@ -1,3 +1,6 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
 package plugin
 
 import (