diff --git a/data/ui/add_contact.ui b/data/ui/add_contact.ui
index e5899ffc01e82111d97537b33d1089c6851744f3..f485cec549e42ee06ce2491c2f847421d4f5d81b 100644
--- a/data/ui/add_contact.ui
+++ b/data/ui/add_contact.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Copyright (c) 2019 Nico Alt
+  SPDX-License-Identifier: AGPL-3.0-only
+  License-Filename: LICENSE.md
+-->
 <interface>
   <requires lib="gtk+" version="3.20"/>
   <object class="GtkGrid" id="add_contact">
diff --git a/data/ui/chat.ui b/data/ui/chat.ui
index c64048e3944451f59080600f34aa17632989c0f7..e779caf6b367c92139824e8d06b8276cfdf32be4 100644
--- a/data/ui/chat.ui
+++ b/data/ui/chat.ui
@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!-- Generated with glade 3.22.1 -->
+<!--
+  Copyright (c) 2019 Nico Alt
+  SPDX-License-Identifier: AGPL-3.0-only
+  License-Filename: LICENSE.md
+-->
 <interface>
   <requires lib="gtk+" version="3.20"/>
   <object class="GtkGrid" id="chat">
diff --git a/data/ui/login.ui b/data/ui/login.ui
index c834a5c623ceddc2024dc5a4689327138cda49b3..3ac5a591e29a06f203d50996f794eb29de10d0b7 100644
--- a/data/ui/login.ui
+++ b/data/ui/login.ui
@@ -1,4 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Copyright (c) 2019 Nico Alt
+  SPDX-License-Identifier: AGPL-3.0-only
+  License-Filename: LICENSE.md
+
+  Based on parts of GNOME Fractal
+  https://gitlab.gnome.org/GNOME/fractal/blob/4.2.2/fractal-gtk/res/ui/login_flow.ui
+-->
 <interface>
   <requires lib="gtk+" version="3.22"/>
   <object class="GtkStack" id="login_flow_stack">
diff --git a/data/ui/main.ui b/data/ui/main.ui
index d0e27de39044baca96cb5d4f67790be1e07d75da..ab14dc861ee6e6121025f89f0eb7c2d9e0c4f6dc 100644
--- a/data/ui/main.ui
+++ b/data/ui/main.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Copyright (c) 2019 Nico Alt
+  SPDX-License-Identifier: AGPL-3.0-only
+  License-Filename: LICENSE.md
+-->
 <interface>
   <requires lib="gtk+" version="3.20"/>
   <object class="GtkListBox" id="contacts_list">
diff --git a/data/ui/registration.ui b/data/ui/registration.ui
index 86a02b03b9216f7385550d0a686cb74dabe5ecbe..32143289ef29f0e7dfb7e13535c0dff77b0ec6c9 100644
--- a/data/ui/registration.ui
+++ b/data/ui/registration.ui
@@ -1,4 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Copyright (c) 2019 Nico Alt
+  SPDX-License-Identifier: AGPL-3.0-only
+  License-Filename: LICENSE.md
+
+  Based on parts of GNOME Fractal
+  https://gitlab.gnome.org/GNOME/fractal/blob/4.2.2/fractal-gtk/res/ui/login_flow.ui
+-->
 <interface>
   <requires lib="gtk+" version="3.22"/>
   <object class="GtkStack" id="registration_flow_stack">
diff --git a/data/ui/toolbar_start.ui b/data/ui/toolbar_start.ui
index 5722aa2a8e617d038d2365084a9558d3af3f679d..31a939280b91719dace4365b13ed95fa7a30167b 100644
--- a/data/ui/toolbar_start.ui
+++ b/data/ui/toolbar_start.ui
@@ -1,6 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!-- Generated with glade 3.22.1 -->
-<!-- Based on https://gitlab.gnome.org/World/lollypop/blob/1.0.12/data/ToolbarPlayback.ui -->
+<!--
+  Copyright (c) 2019 Nico Alt
+  SPDX-License-Identifier: AGPL-3.0-only
+  License-Filename: LICENSE.md
+
+  Based on parts of GNOME Lollypop
+  https://gitlab.gnome.org/World/lollypop/blob/1.0.12/data/ToolbarPlayback.ui
+-->
 <interface>
   <requires lib="gtk+" version="3.10"/>
   <object class="GtkImage" id="back_image">