diff --git a/CHANGES.md b/CHANGES.md
index f034279..20c74e2 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -6,6 +6,7 @@ Changes
 
 ### Rolling release
 
+* 2024-10-22 - Adopt Boost Union class name changes from Boost Union 4.5, raise the dependency to Boost Union 4.5 likewise.
 * 2024-10-22 - Change Moodle-Plugin-CI to run on Moodle Core 4.5
 * 2024-08-11 - Updated Moodle Plugin CI to latest upstream recommendations
 * 2024-07-25 - Development: Rename master branch to main, please update your clones.
diff --git a/lib.php b/lib.php
index 513a62f..6324687 100644
--- a/lib.php
+++ b/lib.php
@@ -29,7 +29,7 @@
 /**
  * Returns the main SCSS content.
  *
- * @param theme_config $theme The theme config object.
+ * @param \core\output\theme_config $theme The theme config object.
  * @return string
  */
 function theme_boost_union_child_get_main_scss_content($theme) {
@@ -40,7 +40,7 @@ function theme_boost_union_child_get_main_scss_content($theme) {
 
     // As a start, get the compiled main SCSS from Boost Union.
     // This way, Boost Union Child will ship the same SCSS code as Boost Union itself.
-    $scss = theme_boost_union_get_main_scss_content(theme_config::load('boost_union'));
+    $scss = theme_boost_union_get_main_scss_content(\core\output\theme_config::load('boost_union'));
 
     // And add Boost Union Child's main SCSS file to the stack.
     $scss .= file_get_contents($CFG->dirroot . '/theme/boost_union_child/scss/post.scss');
@@ -51,7 +51,7 @@ function theme_boost_union_child_get_main_scss_content($theme) {
 /**
  * Get SCSS to prepend.
  *
- * @param theme_config $theme The theme config object.
+ * @param \core\output\theme_config $theme The theme config object.
  * @return string
  */
 function theme_boost_union_child_get_pre_scss($theme) {
@@ -71,7 +71,7 @@ function theme_boost_union_child_get_pre_scss($theme) {
     // This way, we will add the pre SCSS code with the explicit use of the Boost Union configuration to the stack.
     $inheritanceconfig = get_config('theme_boost_union_child', 'prescssinheritance');
     if ($inheritanceconfig == THEME_BOOST_UNION_CHILD_SETTING_INHERITANCE_DUPLICATE) {
-        $scss .= theme_boost_union_get_pre_scss(theme_config::load('boost_union'));
+        $scss .= theme_boost_union_get_pre_scss(\core\output\theme_config::load('boost_union'));
     }
 
     // And add Boost Union Child's pre SCSS file to the stack.
@@ -89,7 +89,7 @@ function theme_boost_union_child_get_pre_scss($theme) {
 /**
  * Inject additional SCSS.
  *
- * @param theme_config $theme The theme config object.
+ * @param \core\output\theme_config $theme The theme config object.
  * @return string
  */
 function theme_boost_union_child_get_extra_scss($theme) {
@@ -109,7 +109,7 @@ function theme_boost_union_child_get_extra_scss($theme) {
     // This way, we will add the extra SCSS code with the explicit use of the Boost Union configuration to the stack.
     $inheritanceconfig = get_config('theme_boost_union_child', 'extrascssinheritance');
     if ($inheritanceconfig == THEME_BOOST_UNION_CHILD_SETTING_INHERITANCE_DUPLICATE) {
-        $scss .= theme_boost_union_get_extra_scss(theme_config::load('boost_union'));
+        $scss .= theme_boost_union_get_extra_scss(\core\output\theme_config::load('boost_union'));
     }
 
     /**********************************************************
@@ -133,7 +133,7 @@ function theme_boost_union_child_extend_busettingsoverview() {
         'label' => get_string('pluginname', 'theme_boost_union_child'),
         'desc' => get_string('settingsoverview_buc_desc', 'theme_boost_union_child'),
         'btn' => 'primary',
-        'url' => new \moodle_url('/admin/settings.php', ['section' => 'theme_boost_union_child']),
+        'url' => new \core\url('/admin/settings.php', ['section' => 'theme_boost_union_child']),
     ];
 
     return $cards;
diff --git a/settings.php b/settings.php
index 8c46040..976f76d 100644
--- a/settings.php
+++ b/settings.php
@@ -36,9 +36,9 @@
     // settings and which is automatically linked from the theme selector page.
     // To avoid that there appears a broken "Boost Union Child" settings page, we redirect the user to a settings
     // overview page if he opens this page.
-    $mainsettingspageurl = new moodle_url('/admin/settings.php', ['section' => 'themesettingboost_union_child']);
+    $mainsettingspageurl = new \core\url('/admin/settings.php', ['section' => 'themesettingboost_union_child']);
     if ($ADMIN->fulltree && $PAGE->has_set_url() && $PAGE->url->compare($mainsettingspageurl)) {
-        redirect(new moodle_url('/admin/settings.php', ['section' => 'theme_boost_union_child']));
+        redirect(new \core\url('/admin/settings.php', ['section' => 'theme_boost_union_child']));
     }
 
     // Create empty settings page structure to make the site administration work on non-admin pages.
diff --git a/version.php b/version.php
index 194765b..196eb80 100644
--- a/version.php
+++ b/version.php
@@ -27,4 +27,4 @@
 $plugin->component = 'theme_boost_union_child';
 $plugin->version = 2024010100;
 $plugin->maturity = MATURITY_STABLE;
-$plugin->dependencies = ['theme_boost_union' => 2023010548];
+$plugin->dependencies = ['theme_boost_union' => 2024100700];