diff --git a/src/backends/base.js b/src/backends/base.js
index 61d3166ff0c74f294edd483fbe315c6fcec21481..1736e6f5021648ac3b752365a0d4dfc569a2bd3c 100644
--- a/src/backends/base.js
+++ b/src/backends/base.js
@@ -1,3 +1,18 @@
+/* Copyright 2021 Dominik George <nik@naturalnet.de>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 class BaseBackend() {
 }
 
diff --git a/src/backends/widget.js b/src/backends/widget.js
index 69f883f51fd30312a0f6a12567777e6df3cd0a73..bfee43956950d96e8cbb8fa310fcb59eb125eaf5 100644
--- a/src/backends/widget.js
+++ b/src/backends/widget.js
@@ -1,3 +1,18 @@
+/* Copyright 2021 Dominik George <nik@naturalnet.de>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 import BaseBackend from './base';
 import WidgetApi from 'matrix-widget-api';
 
diff --git a/src/frontend/game.js b/src/frontend/game.js
index 74e765092d1b02605c12a5d8c81cea42761c226d..eba46c1bec8f8197cc4a392c653e21a2ad4934cf 100644
--- a/src/frontend/game.js
+++ b/src/frontend/game.js
@@ -1,3 +1,18 @@
+/* Copyright 2021 Dominik George <nik@naturalnet.de>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 import Phaser from 'phaser';
 import TestScene from './scenes/test';
 
diff --git a/src/frontend/scenes/test.js b/src/frontend/scenes/test.js
index 9ca189fdbbe413e4f115ce21828999f9a879d152..020f3778467383ce88d9f864510fa02d8fb76516 100644
--- a/src/frontend/scenes/test.js
+++ b/src/frontend/scenes/test.js
@@ -1,3 +1,18 @@
+/* Copyright 2021 Dominik George <nik@naturalnet.de>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 function preload () {
   this.load.image('404', 'http://labs.phaser.io/assets/sprites/phaser3-logo.png')
 }
diff --git a/src/widget.js b/src/widget.js
index d96e46c643b37bbfefe6f12dff40116a037e6e70..fcd51e895035a727cb226b390d99664f01bae767 100644
--- a/src/widget.js
+++ b/src/widget.js
@@ -1,3 +1,18 @@
+/* Copyright 2021 Dominik George <nik@naturalnet.de>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 import WidgetBackend from './backends/widget';
 import Game from './frontend/game';