diff --git a/core/lib/Drupal/Core/Path/AliasManager.php b/core/lib/Drupal/Core/Path/AliasManager.php
index 8a4b7ed..da3555b 100644
--- a/core/lib/Drupal/Core/Path/AliasManager.php
+++ b/core/lib/Drupal/Core/Path/AliasManager.php
@@ -222,7 +222,7 @@ protected function lookupPathSource($path, $langcode) {
       // Look for the value $path within the cached $map
       $source = isset($this->lookupMap[$langcode]) ? array_search($path, $this->lookupMap[$langcode]) : FALSE;
       if (!$source) {
-        if ($source = $this->path->lookupPathAlias($path, $langcode)) {
+        if ($source = $this->path->lookupPathSource($path, $langcode)) {
           $this->lookupMap[$langcode][$source] = $path;
         }
         else {
diff --git a/core/lib/Drupal/Core/Path/Path.php b/core/lib/Drupal/Core/Path/Path.php
index d63cf08..74aeae0 100644
--- a/core/lib/Drupal/Core/Path/Path.php
+++ b/core/lib/Drupal/Core/Path/Path.php
@@ -159,13 +159,13 @@ public function preloadPathAlias($preloaded, $langcode) {
       ':langcode' => $langcode,
       ':langcode_undetermined' => Language::LANGCODE_NOT_SPECIFIED,
     );
-    // Always get the language-specific alias before the language-neutral
-    // one. For example 'de' is less than 'und' so the order needs to be
-    // ASC, while 'xx-lolspeak' is more than 'und' so the order needs to
-    // be DESC. We also order by pid ASC so that fetchAllKeyed() returns
-    // the most recently created alias for each source. Subsequent queries
-    // using fetchField() must use pid DESC to have the same effect.
-    // For performance reasons, the query builder is not used here.
+    // Always get the language-specific alias before the language-neutral one.
+    // For example 'de' is less than 'und' so the order needs to be ASC, while
+    // 'xx-lolspeak' is more than 'und' so the order needs to be DESC. We also
+    // order by pid ASC so that fetchAllKeyed() returns the most recently
+    // created alias for each source. Subsequent queries using fetchField() must
+    // use pid DESC to have the same effect. For performance reasons, the query
+    // builder is not used here.
     if ($langcode == Language::LANGCODE_NOT_SPECIFIED) {
       // Prevent PDO from complaining about a token the query doesn't use.
       unset($args[':langcode']);
@@ -182,16 +182,15 @@ public function preloadPathAlias($preloaded, $langcode) {
   }
 
   /**
-   * Given a path source, return its path alias if one exists. Otherwise,
-   * return FALSE.
+   * Given a path source, return its path alias or FALSE is non-existing.
    *
-   * @param $path
+   * @param string $path
    *   The path to investigate for corresponding path aliases.
-   * @param $langcode
+   * @param string $langcode
    *   Language code to search the path with. If there's no path defined for
    *   that language it will search paths without language.
    *
-   * @return
+   * @return string|bool
    *   A path alias, or FALSE if no path was found.
    */
   public function lookupPathAlias($path, $langcode) {
@@ -216,16 +215,15 @@ public function lookupPathAlias($path, $langcode) {
   }
 
   /**
-   * Given an alias, return its Drupal system URL if one exists. Otherwise,
-   * return FALSE.
+   * Given an alias, return its Drupal system URL or FALSE if non-existing.
    *
-   * @param $path
+   * @param string $path
    *   The path to investigate for corresponding system URLs.
-   * @param $langcode
+   * @param string $langcode
    *   Language code to search the path with. If there's no path defined for
    *   that language it will search paths without language.
    *
-   * @return
+   * @return string|bool
    *   A Drupal system path, or FALSE if no path was found.
    */
   public function lookupPathSource($path, $langcode) {