diff --git a/core/modules/system/src/Tests/Theme/ThemeInfoTest.php b/core/modules/system/src/Tests/Theme/ThemeInfoTest.php
index 7d76840..d0301ad 100644
--- a/core/modules/system/src/Tests/Theme/ThemeInfoTest.php
+++ b/core/modules/system/src/Tests/Theme/ThemeInfoTest.php
@@ -95,13 +95,13 @@ public function testChanges() {
     $active_theme = $this->themeManager->getActiveTheme();
     // Make sure we are not testing the wrong theme.
     $this->assertEqual('test_theme', $active_theme->getName());
-    $this->assertEqual(['classy/base', 'core/normalize', 'test_theme/global-styling'], $active_theme->getLibraries());
+    $this->assertEqual(['classy/base', 'core/normalize', 'classy/action-links', 'classy/breadcrumb', 'classy/button', 'test_theme/global-styling'], $active_theme->getLibraries());
 
     // @see theme_test_system_info_alter()
     $this->state->set('theme_test.modify_info_files', TRUE);
     drupal_flush_all_caches();
     $active_theme = $this->themeManager->getActiveTheme();
-    $this->assertEqual(['classy/base', 'core/normalize', 'test_theme/global-styling', 'core/backbone'], $active_theme->getLibraries());
+    $this->assertEqual(['classy/base', 'core/normalize', 'classy/action-links', 'classy/breadcrumb', 'classy/button', 'test_theme/global-styling', 'core/backbone'], $active_theme->getLibraries());
   }
 
 }
diff --git a/core/modules/system/system.libraries.yml b/core/modules/system/system.libraries.yml
index 9493f52..f66cb4f 100644
--- a/core/modules/system/system.libraries.yml
+++ b/core/modules/system/system.libraries.yml
@@ -20,9 +20,6 @@ base:
       css/components/sticky-header.module.css: { weight: -10 }
       css/components/tabledrag.module.css: { weight: -10 }
     theme:
-      css/components/action-links.theme.css: { weight: -10 }
-      css/components/breadcrumb.theme.css: { weight: -10 }
-      css/components/button.theme.css: { weight: -10 }
       css/components/collapse-processed.theme.css: { weight: -10 }
       css/components/container-inline.theme.css: { weight: -10 }
       css/components/details.theme.css: { weight: -10 }
diff --git a/core/themes/classy/classy.info.yml b/core/themes/classy/classy.info.yml
index bd61ce0..c63422a 100644
--- a/core/themes/classy/classy.info.yml
+++ b/core/themes/classy/classy.info.yml
@@ -8,3 +8,6 @@ core: 8.x
 libraries:
   - classy/base
   - core/normalize
+  - classy/action-links
+  - classy/breadcrumb
+  - classy/button
diff --git a/core/themes/classy/classy.libraries.yml b/core/themes/classy/classy.libraries.yml
index af0f891..374f8dc 100644
--- a/core/themes/classy/classy.libraries.yml
+++ b/core/themes/classy/classy.libraries.yml
@@ -27,3 +27,21 @@ search.results:
   css:
     theme:
       css/search/search.theme.css: {}
+
+action-links:
+  version: VERSION
+  css:
+    theme:
+      css/components/action-links.css: {}
+
+breadcrumb:
+  version: VERSION
+  css:
+    theme:
+      css/components/breadcrumb.css: {}
+
+button:
+  version: VERSION
+  css:
+    theme:
+      css/components/button.css: {}
diff --git a/core/modules/system/css/components/action-links.theme.css b/core/themes/classy/css/components/action-links.css
similarity index 100%
rename from core/modules/system/css/components/action-links.theme.css
rename to core/themes/classy/css/components/action-links.css
diff --git a/core/modules/system/css/components/breadcrumb.theme.css b/core/themes/classy/css/components/breadcrumb.css
similarity index 100%
rename from core/modules/system/css/components/breadcrumb.theme.css
rename to core/themes/classy/css/components/breadcrumb.css
diff --git a/core/modules/system/css/components/button.theme.css b/core/themes/classy/css/components/button.css
similarity index 100%
rename from core/modules/system/css/components/button.theme.css
rename to core/themes/classy/css/components/button.css