diff --git a/src/content/contentAreaUtils.d.ts b/src/content/contentAreaUtils.d.ts
index 8e782aa..26aaa4b 100644
--- a/src/content/contentAreaUtils.d.ts
+++ b/src/content/contentAreaUtils.d.ts
@@ -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 http://mozilla.org/MPL/2.0/. */
+
 declare function urlSecurityCheck(
   url: string | nsIURIType,
   principal: nsIPrincipalType,
diff --git a/src/content/globalOverlay.d.ts b/src/content/globalOverlay.d.ts
index 9abbf37..136516d 100644
--- a/src/content/globalOverlay.d.ts
+++ b/src/content/globalOverlay.d.ts
@@ -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 http://mozilla.org/MPL/2.0/. */
+
 declare function closeWindow(aClose, aPromptFunction, aSource)
 
 /**
diff --git a/src/content/shared/contextMenus/menuItems.ts b/src/content/shared/contextMenus/menuItems.ts
index 72c6bd5..63260f9 100644
--- a/src/content/shared/contextMenus/menuItems.ts
+++ b/src/content/shared/contextMenus/menuItems.ts
@@ -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 http://mozilla.org/MPL/2.0/. */
+
 import curry from 'fnts/curry'
 
 import type { MenuItemAction, VisibilityCheck } from '.'