diff --git a/core/lib/Drupal/Core/Path/PathMatcher.php b/core/lib/Drupal/Core/Path/PathMatcher.php
index 9a8a7bf..449ba2b 100644
--- a/core/lib/Drupal/Core/Path/PathMatcher.php
+++ b/core/lib/Drupal/Core/Path/PathMatcher.php
@@ -48,11 +48,9 @@ public function __construct(ConfigFactoryInterface $config_factory) {
   /**
    * {@inheritdoc}
    */
-  public function matchPath($path, array $patterns) {
-    // Convert array to a string for easier find and replace.
-    $pattern_string = implode("\n", $patterns);
+  public function matchPath($path, $patterns) {
 
-    if (!isset($this->regexes[$pattern_string])) {
+    if (!isset($this->regexes[$patterns])) {
       // Lazy-load front page config.
       if (!isset($this->frontPage)) {
         $this->frontPage = $this->configFactory->get('system.site')->get('page.front');
@@ -71,9 +69,9 @@ public function matchPath($path, array $patterns) {
         '.*',
         '\1' . preg_quote($this->frontPage, '/') . '\2',
       );
-      $patterns_quoted = preg_quote($pattern_string, '/');
-      $this->regexes[$pattern_string] = '/^(' . preg_replace($to_replace, $replacements, $patterns_quoted) . ')$/';
+      $patterns_quoted = preg_quote($patterns, '/');
+      $this->regexes[$patterns] = '/^(' . preg_replace($to_replace, $replacements, $patterns_quoted) . ')$/';
     }
-    return (bool) preg_match($this->regexes[$pattern_string], $path);
+    return (bool) preg_match($this->regexes[$patterns], $path);
   }
 }
diff --git a/core/lib/Drupal/Core/Path/PathMatcherInterface.php b/core/lib/Drupal/Core/Path/PathMatcherInterface.php
index 402641b..8c0b800 100644
--- a/core/lib/Drupal/Core/Path/PathMatcherInterface.php
+++ b/core/lib/Drupal/Core/Path/PathMatcherInterface.php
@@ -17,12 +17,12 @@
    *
    * @param string $path
    *   The path to match.
-   * @param string[] $patterns
-   *   A set of patterns.
+   * @param string $patterns
+   *   A set of patterns separated by a newline.
    *
    * @return bool
    *   TRUE if the path matches a pattern, FALSE otherwise.
    */
-  public function matchPath($path, array $patterns);
+  public function matchPath($path, $patterns);
 
 }
diff --git a/core/tests/Drupal/Tests/Core/Path/PathMatcherTest.php b/core/tests/Drupal/Tests/Core/Path/PathMatcherTest.php
index adfdc0b..9c36e2a 100644
--- a/core/tests/Drupal/Tests/Core/Path/PathMatcherTest.php
+++ b/core/tests/Drupal/Tests/Core/Path/PathMatcherTest.php
@@ -53,7 +53,6 @@ public function setUp() {
       )
     );
     $this->pathMatcher = new PathMatcher($config_factory_stub);
-    $this->patterns = "my/pass/page\r\nmy/pass/page2\r\nfoo";
   }
 
 
@@ -89,12 +88,12 @@ public function getMatchPathData() {
     return array(
       // Match explicit path pattern.
       array(
-        array('my/pass/page', 'my/pass/page2', 'foo'),
+        "my/pass/page\r\nmy/pass/page2\r\nfoo",
         array('my/pass/page', 'my/pass/page2'),
       ),
       // Match wildcard path pattern.
       array(
-        array('my/pass/*'),
+        'my/pass/*',
         array('my/pass/page3'),
       ),
     );
@@ -109,7 +108,7 @@ public function getMatchPathData() {
   public function getNoMatchPathData() {
     return array(
       array(
-        array('my/pass/page', 'my/pass/page2', 'foo'),
+        "my/pass/page\r\nmy/pass/page2\r\nfoo",
         array('my/pass/page4'),
       ),
     );