core/lib/Drupal/Core/Asset/LibraryDiscoveryCollector.php | 2 +-
 core/lib/Drupal/Core/Theme/ActiveTheme.php               | 2 +-
 core/lib/Drupal/Core/Theme/ThemeInitialization.php       | 4 ++--
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/core/lib/Drupal/Core/Asset/LibraryDiscoveryCollector.php b/core/lib/Drupal/Core/Asset/LibraryDiscoveryCollector.php
index f0a590a..805d117 100644
--- a/core/lib/Drupal/Core/Asset/LibraryDiscoveryCollector.php
+++ b/core/lib/Drupal/Core/Asset/LibraryDiscoveryCollector.php
@@ -127,7 +127,7 @@ protected function getLibraryDefinitions($extension) {
         }
       }
       else {
-        // If libraries are not overridden, then apply libraries extend.
+        // If libraries are not overridden, then apply libraries-extend.
         $libraries[$name] = $this->applyLibrariesExtend($extension, $name, $definition);
       }
     }
diff --git a/core/lib/Drupal/Core/Theme/ActiveTheme.php b/core/lib/Drupal/Core/Theme/ActiveTheme.php
index 3b43cc0..44cd04a 100644
--- a/core/lib/Drupal/Core/Theme/ActiveTheme.php
+++ b/core/lib/Drupal/Core/Theme/ActiveTheme.php
@@ -225,7 +225,7 @@ public function getLibrariesOverride() {
    * Returns the libraries extended by the active theme.
    *
    * @return array
-   *   The list of libraries extend.
+   *   The list of libraries-extend definitions.
    */
   public function getLibrariesExtend() {
     return $this->librariesExtend;
diff --git a/core/lib/Drupal/Core/Theme/ThemeInitialization.php b/core/lib/Drupal/Core/Theme/ThemeInitialization.php
index e310777..95f27a9 100644
--- a/core/lib/Drupal/Core/Theme/ThemeInitialization.php
+++ b/core/lib/Drupal/Core/Theme/ThemeInitialization.php
@@ -185,7 +185,7 @@ public function getActiveTheme(Extension $theme, array $base_themes = []) {
       }
     }
 
-    // Get libraries extend declared by base themes.
+    // Get libraries extensions declared by base themes.
     foreach ($base_themes as $base) {
       if (!empty($base->info['libraries-extend'])) {
         foreach ($base->info['libraries-extend'] as $library => $extend) {
@@ -200,7 +200,7 @@ public function getActiveTheme(Extension $theme, array $base_themes = []) {
         }
       }
     }
-    // Add libraries extend declared by this theme.
+    // Add libraries extensions declared by this theme.
     if (!empty($theme->info['libraries-extend'])) {
       foreach ($theme->info['libraries-extend'] as $library => $extend) {
         if (isset($values['libraries_extend'][$library])) {