diff --git a/tests/samples/accessibility.ui b/tests/samples/accessibility.ui
index 321f20f..7732a14 100644
--- a/tests/samples/accessibility.ui
+++ b/tests/samples/accessibility.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkBox">
diff --git a/tests/samples/action_widgets.ui b/tests/samples/action_widgets.ui
index 91b6e64..ac730a2 100644
--- a/tests/samples/action_widgets.ui
+++ b/tests/samples/action_widgets.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkDialog">
diff --git a/tests/samples/adw_breakpoint.ui b/tests/samples/adw_breakpoint.ui
index b2d5ec3..f667958 100644
--- a/tests/samples/adw_breakpoint.ui
+++ b/tests/samples/adw_breakpoint.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkLabel" id="label"></object>
diff --git a/tests/samples/child_type.ui b/tests/samples/child_type.ui
index df9386e..56f03eb 100644
--- a/tests/samples/child_type.ui
+++ b/tests/samples/child_type.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkWindow">
diff --git a/tests/samples/combo_box_text.ui b/tests/samples/combo_box_text.ui
index bb234d3..c160d80 100644
--- a/tests/samples/combo_box_text.ui
+++ b/tests/samples/combo_box_text.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkComboBoxText">
diff --git a/tests/samples/comments.ui b/tests/samples/comments.ui
index b916a09..bd3378a 100644
--- a/tests/samples/comments.ui
+++ b/tests/samples/comments.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GObject"></object>
diff --git a/tests/samples/enum.ui b/tests/samples/enum.ui
index d2cda1e..e6ad9d4 100644
--- a/tests/samples/enum.ui
+++ b/tests/samples/enum.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkScrolledWindow">
diff --git a/tests/samples/expr_closure.ui b/tests/samples/expr_closure.ui
index 1581d65..46300da 100644
--- a/tests/samples/expr_closure.ui
+++ b/tests/samples/expr_closure.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkLabel" id="my-label">
diff --git a/tests/samples/expr_closure_args.ui b/tests/samples/expr_closure_args.ui
index 1b539ac..6c702d9 100644
--- a/tests/samples/expr_closure_args.ui
+++ b/tests/samples/expr_closure_args.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkLabel">
diff --git a/tests/samples/expr_lookup.ui b/tests/samples/expr_lookup.ui
index 91d7590..16172d4 100644
--- a/tests/samples/expr_lookup.ui
+++ b/tests/samples/expr_lookup.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkOverlay">
diff --git a/tests/samples/file_filter.ui b/tests/samples/file_filter.ui
index 1cb0114..6ac8717 100644
--- a/tests/samples/file_filter.ui
+++ b/tests/samples/file_filter.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkFileFilter">
diff --git a/tests/samples/flags.ui b/tests/samples/flags.ui
index 56fbf31..2f0a26e 100644
--- a/tests/samples/flags.ui
+++ b/tests/samples/flags.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GApplication">
diff --git a/tests/samples/id_prop.ui b/tests/samples/id_prop.ui
index 4940824..cece573 100644
--- a/tests/samples/id_prop.ui
+++ b/tests/samples/id_prop.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkScale">
diff --git a/tests/samples/issue_119.ui b/tests/samples/issue_119.ui
index 2e039b5..b574549 100644
--- a/tests/samples/issue_119.ui
+++ b/tests/samples/issue_119.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkAdjustment">
diff --git a/tests/samples/layout.ui b/tests/samples/layout.ui
index 027d010..a8c294f 100644
--- a/tests/samples/layout.ui
+++ b/tests/samples/layout.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkGrid">
diff --git a/tests/samples/list_factory.ui b/tests/samples/list_factory.ui
index 447a53a..a1e7c27 100644
--- a/tests/samples/list_factory.ui
+++ b/tests/samples/list_factory.ui
@@ -1,10 +1,20 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkListView">
     <property name="factory">
       <object class="GtkBuilderListItemFactory" id="list_item_factory">
         <property name="bytes"><![CDATA[<?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <template class="GtkListItem">
     <property name="child">
diff --git a/tests/samples/menu.ui b/tests/samples/menu.ui
index 3b19896..71c3fd2 100644
--- a/tests/samples/menu.ui
+++ b/tests/samples/menu.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <menu id="my-menu">
diff --git a/tests/samples/numbers.ui b/tests/samples/numbers.ui
index 813afe4..b0f9a6b 100644
--- a/tests/samples/numbers.ui
+++ b/tests/samples/numbers.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkLabel">
diff --git a/tests/samples/object_prop.ui b/tests/samples/object_prop.ui
index 5224073..d338a66 100644
--- a/tests/samples/object_prop.ui
+++ b/tests/samples/object_prop.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkRange">
diff --git a/tests/samples/parseable.ui b/tests/samples/parseable.ui
index 231a25c..c24ee2c 100644
--- a/tests/samples/parseable.ui
+++ b/tests/samples/parseable.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkShortcut">
diff --git a/tests/samples/placeholder.ui b/tests/samples/placeholder.ui
index 82d4360..4e703e2 100644
--- a/tests/samples/placeholder.ui
+++ b/tests/samples/placeholder.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkBox">
diff --git a/tests/samples/property.ui b/tests/samples/property.ui
index ba8089d..1bf9e9c 100644
--- a/tests/samples/property.ui
+++ b/tests/samples/property.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkBox">
diff --git a/tests/samples/property_binding.ui b/tests/samples/property_binding.ui
index c496366..d14e50d 100644
--- a/tests/samples/property_binding.ui
+++ b/tests/samples/property_binding.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkBox">
diff --git a/tests/samples/responses.ui b/tests/samples/responses.ui
index ba26de5..48122ca 100644
--- a/tests/samples/responses.ui
+++ b/tests/samples/responses.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="AdwMessageDialog">
diff --git a/tests/samples/scale_marks.ui b/tests/samples/scale_marks.ui
index 719f888..36956f5 100644
--- a/tests/samples/scale_marks.ui
+++ b/tests/samples/scale_marks.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkScale">
diff --git a/tests/samples/signal.ui b/tests/samples/signal.ui
index b361d69..8163ca3 100644
--- a/tests/samples/signal.ui
+++ b/tests/samples/signal.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkEntry">
diff --git a/tests/samples/size_group.ui b/tests/samples/size_group.ui
index 218b023..a222485 100644
--- a/tests/samples/size_group.ui
+++ b/tests/samples/size_group.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkSizeGroup">
diff --git a/tests/samples/string_list.ui b/tests/samples/string_list.ui
index 156bc09..74de992 100644
--- a/tests/samples/string_list.ui
+++ b/tests/samples/string_list.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkStringList" id="greetings">
diff --git a/tests/samples/strings.ui b/tests/samples/strings.ui
index b8ca96a..1dea963 100644
--- a/tests/samples/strings.ui
+++ b/tests/samples/strings.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkLabel">
diff --git a/tests/samples/style.ui b/tests/samples/style.ui
index a216fdb..c625a3f 100644
--- a/tests/samples/style.ui
+++ b/tests/samples/style.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkLabel">
diff --git a/tests/samples/subscope.ui b/tests/samples/subscope.ui
index 61bdc18..693a774 100644
--- a/tests/samples/subscope.ui
+++ b/tests/samples/subscope.ui
@@ -1,8 +1,18 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkBuilderListItemFactory">
     <property name="bytes"><![CDATA[<?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <template class="GtkListItem">
     <property name="child">
diff --git a/tests/samples/template.ui b/tests/samples/template.ui
index aebec5e..ea9c8b4 100644
--- a/tests/samples/template.ui
+++ b/tests/samples/template.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <template class="TestTemplate" parent="GtkApplicationWindow">
diff --git a/tests/samples/template_bind_property.ui b/tests/samples/template_bind_property.ui
index eb55547..8dac57b 100644
--- a/tests/samples/template_bind_property.ui
+++ b/tests/samples/template_bind_property.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <template class="MyTemplate">
diff --git a/tests/samples/template_binding.ui b/tests/samples/template_binding.ui
index 7c8b49d..e8b2455 100644
--- a/tests/samples/template_binding.ui
+++ b/tests/samples/template_binding.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <template class="MyTemplate" parent="GtkBox">
diff --git a/tests/samples/template_binding_extern.ui b/tests/samples/template_binding_extern.ui
index 2bbc88f..f67b09c 100644
--- a/tests/samples/template_binding_extern.ui
+++ b/tests/samples/template_binding_extern.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <template class="MyTemplate" parent="MyParentClass">
diff --git a/tests/samples/template_id.ui b/tests/samples/template_id.ui
index c7791b2..352cd2e 100644
--- a/tests/samples/template_id.ui
+++ b/tests/samples/template_id.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <template class="MyTemplate" parent="GtkButton">
diff --git a/tests/samples/template_no_parent.ui b/tests/samples/template_no_parent.ui
index ea2263e..1f06584 100644
--- a/tests/samples/template_no_parent.ui
+++ b/tests/samples/template_no_parent.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <template class="GtkListItem"></template>
diff --git a/tests/samples/template_simple_binding.ui b/tests/samples/template_simple_binding.ui
index 41788e4..d858a86 100644
--- a/tests/samples/template_simple_binding.ui
+++ b/tests/samples/template_simple_binding.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <template class="MyTemplate">
diff --git a/tests/samples/translated.ui b/tests/samples/translated.ui
index 6f84d40..66102a0 100644
--- a/tests/samples/translated.ui
+++ b/tests/samples/translated.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkLabel">
diff --git a/tests/samples/typeof.ui b/tests/samples/typeof.ui
index 4c45869..4157496 100644
--- a/tests/samples/typeof.ui
+++ b/tests/samples/typeof.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GListStore">
diff --git a/tests/samples/uint.ui b/tests/samples/uint.ui
index d64f298..f96f15f 100644
--- a/tests/samples/uint.ui
+++ b/tests/samples/uint.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GtkFlowBox">
diff --git a/tests/samples/unchecked_class.ui b/tests/samples/unchecked_class.ui
index 6518cfe..9c5ac34 100644
--- a/tests/samples/unchecked_class.ui
+++ b/tests/samples/unchecked_class.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="MyComponent" id="component">
diff --git a/tests/samples/using.ui b/tests/samples/using.ui
index 5b81551..28dbb01 100644
--- a/tests/samples/using.ui
+++ b/tests/samples/using.ui
@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
 <interface>
   <requires lib="gtk" version="4.0"/>
   <object class="GObject"></object>