diff --git a/src/apps/actor/base-sheet.js b/src/apps/actor/base-sheet.js
index 20d39719..47ba2c18 100644
--- a/src/apps/actor/base-sheet.js
+++ b/src/apps/actor/base-sheet.js
@@ -1,4 +1,7 @@
 // SPDX-FileCopyrightText: 2021 Johannes Loher
+// SPDX-FileCopyrightText: 2021 Oliver Rümpelein
+// SPDX-FileCopyrightText: 2021 Gesina Schwalbe
+// SPDX-FileCopyrightText: 2021 Siegfried Krug
 //
 // SPDX-License-Identifier: MIT