diff --git a/core/includes/token.inc b/core/includes/token.inc
index 5cbb4ee..b1dd717 100644
--- a/core/includes/token.inc
+++ b/core/includes/token.inc
@@ -114,13 +114,13 @@ function token_replace($text, array $data = array(), array $options = array()) {
  */
 function token_scan($text) {
   // Matches tokens with the following pattern: [$type:$name]
-  // $type and $name may not contain [ ] or whitespace characters.
-  // $type may not contain : characters, but $name may.
+  // $type and $name may not contain [ ] characters.
+  // $type may not contain : or whitespace characters, but $name may.
   preg_match_all('/
     \[             # [ - pattern start
     ([^\s\[\]:]*)  # match $type not containing whitespace : [ or ]
     :              # : - separator
-    ([^\s\[\]]*)   # match $name not containing whitespace [ or ]
+    ([^\[\]]*)     # match $name not containing [ or ]
     \]             # ] - pattern end
     /x', $text, $matches);
 
diff --git a/core/modules/system/lib/Drupal/system/Tests/System/TokenScanTest.php b/core/modules/system/lib/Drupal/system/Tests/System/TokenScanTest.php
new file mode 100644
index 0000000..fffe6ae
--- /dev/null
+++ b/core/modules/system/lib/Drupal/system/Tests/System/TokenScanTest.php
@@ -0,0 +1,42 @@
+<?php
+
+/**
+ * @file
+ * Contains Drupal\system\Tests\System\TokenScanTest.
+ */
+
+namespace Drupal\system\Tests\System;
+
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Test token replacement in strings.
+ */
+class TokenScanTest extends WebTestBase {
+
+  public static function getInfo() {
+    return array(
+      'name' => 'Token scanning',
+      'description' => 'Scan token-like patterns in a dummy text to check token scanning.',
+      'group' => 'System',
+    );
+  }
+
+  /**
+   * Scans dummy text, then tests the output.
+   */
+  function testTokenScan() {
+    // Define text with valid and not valid, fake and existing token-like
+    // strings.
+    $text = 'First a [valid:simple], but dummy token, and a dummy [valid:token with: spaces].';
+    $text .= 'Then a [not valid:token].';
+    $text .= 'Last an existing token: [node:author:name].';
+    $token_wannabes = token_scan($text);
+
+    $this->assertTrue(isset($token_wannabes['valid']['simple']), 'A simple valid token has been matched.');
+    $this->assertTrue(isset($token_wannabes['valid']['token with: spaces']), 'A valid token with space characters in the token name has been matched.');
+    $this->assertFalse(isset($token_wannabes['not valid']), 'An invalid token with spaces in the token type has not been matched.');
+    $this->assertTrue(isset($token_wannabes['node']), 'An existing valid token has been matched.');
+  }
+
+}