diff --git a/core/lib/Drupal/Component/Transliteration/PhpTransliteration.php b/core/lib/Drupal/Component/Transliteration/PhpTransliteration.php
index 7911f64..1ff9d36 100644
--- a/core/lib/Drupal/Component/Transliteration/PhpTransliteration.php
+++ b/core/lib/Drupal/Component/Transliteration/PhpTransliteration.php
@@ -82,26 +82,24 @@ public function removeDiacritics($string) {
     $result = '';
 
     foreach (preg_split('//u', $string, 0, PREG_SPLIT_NO_EMPTY) as $character) {
-      $to_add = $character;
       $code = self::ordUTF8($character);
 
-      // unicode range 0x00bf to 0x017f
+      // These two Unicode ranges include the accented US-ASCII letters, with a few characters
+      // that aren't accented letters mixed in. So define the ranges and the excluded characters.
       $range1 = $code > 0x00bf && $code < 0x017f;
-      $exclusions_r1_x00 = array(0x00c6, 0x00d0, 0x00d7, 0x00de, 0x00df, 0x00e6, 0x00f0, 0x00f7, 0x00fe);
-      $exclusions_r1_x01 = array(0x0132, 0x0133, 0x0138, 0x0149, 0x014a, 0x014b, 0x0152, 0x0153);
-      $exclusions_range1 = array_merge($exclusions_r1_x00, $exclusions_r1_x01);
-
-      // unicode range 01CD to 024F
+      $exclusions_range1 = array(0x00d0, 0x00d7, 0x00f0, 0x00f7, 0x0138, 0x014a, 0x014b);
       $range2 = $code > 0x01cc && $code < 0x0250;
-      $exclusions_r2_x01 = array(0x01DD, 0x01e2, 0x01e3, 0x01ee, 0x01ef, 0x01f1, 0x01f2, 0x01f3, 0x01f6, 0x01f7, 0x01fc, 0x01fd, 0x021c, 0x021d);
-      $exclusions_r2_x02 = array(0x0220, 0x0221, 0x0222, 0x0223, 0x0238, 0x0239, 0x0241, 0x0242, 0x0245);
-      $exclusions_range2 = array_merge($exclusions_r2_x01, $exclusions_r2_x02);
+      $exclusions_range2 = array(0x01DD, 0x01f7, 0x021c, 0x021d, 0x0220, 0x0221, 0x0241, 0x0242, 0x0245);
 
+      $replacement = $character;
       if (($range1 && !in_array($code, $exclusions_range1)) || ($range2 && !in_array($code, $exclusions_range2))) {
-        $to_add = $this->lookupReplacement($code);
+        $to_add = $this->lookupReplacement($code, 'xyz');
+        if(strlen($to_add) === 1) {
+          $replacement = $to_add;
+        }
       }
 
-      $result .= $to_add;
+      $result .= $replacement;
     }
 
     return $result;
@@ -184,7 +182,8 @@ protected static function ordUTF8($character) {
    *
    * @return string
    *   US-ASCII replacement character. If it has a mapping, it is returned;
-   *   otherwise, $unknown_character is returned.
+   *   otherwise, $unknown_character is returned. The replacement can contain
+   *   multiple characters.
    */
   protected function replace($code, $langcode, $unknown_character) {
     if ($code < 0x80) {
@@ -204,17 +203,18 @@ protected function replace($code, $langcode, $unknown_character) {
   }
 
   /**
-   * Lookup the replacement for a certain UTF-8 character code.
+   * Look up the generic replacement for a UTF-8 character code.
    *
    * @param $code
-   *  The UTF-8 character code.
+   *   The UTF-8 character code.
    * @param string $unknown_character
-   *  (optional) The character to substitute for characters without transliterated
-   *  equivalents.
+   *   (optional) The character to substitute for characters without entries in
+   *   the replacement tables
    *
    * @return string
-   *  US-ASCII replacement character. If it has a mapping, it is returned;
-   *  otherwise, $unknown_character is returned.
+   *   US-ASCII replacement characters. If it has a mapping, it is returned;
+   *   otherwise, $unknown_character is returned. The replacement can contain
+   *   multiple characters.
    */
   protected function lookupReplacement($code, $unknown_character = '?') {
     // See if there is a generic mapping for this character.
diff --git a/core/lib/Drupal/Component/Transliteration/TransliterationInterface.php b/core/lib/Drupal/Component/Transliteration/TransliterationInterface.php
index 5107bf3..4d088ef 100644
--- a/core/lib/Drupal/Component/Transliteration/TransliterationInterface.php
+++ b/core/lib/Drupal/Component/Transliteration/TransliterationInterface.php
@@ -19,9 +19,8 @@
    *
    * This only applies to certain letters: Accented Latin characters like
    * a-with-acute-accent, in the UTF-8 character range of 0xE0 to 0xE6 and
-   * 01CD to 024F. Replacements that would result in zero or two characters are
-   * excluded as well as characters that would need afull transliteration
-   * (e.g. Eth, Multiply, Divide etc.).
+   * 01CD to 024F. Replacements that would result in the string changing length
+   * are excluded, as well as characters that are not accented US-ASCII letters.
    *
    * @param string $string
    *   The string holding diacritics.
@@ -52,5 +51,4 @@ public function removeDiacritics($string);
    *   characters, and unknown characters replaced with $unknown_character.
    */
   public function transliterate($string, $langcode = 'en', $unknown_character = '?', $max_length = NULL);
-
 }
diff --git a/core/modules/search/search.module b/core/modules/search/search.module
index ac27c25..e5a5199 100644
--- a/core/modules/search/search.module
+++ b/core/modules/search/search.module
@@ -241,6 +241,9 @@ function search_simplify($text, $langcode = NULL) {
   // Lowercase
   $text = Unicode::strtolower($text);
 
+  // Remove diacitics.
+  $text = \Drupal::service('transliteration')->removeDiacritics($text);
+
   // Call an external processor for word handling.
   search_invoke_preprocess($text, $langcode);
 
@@ -392,9 +395,6 @@ function search_index($type, $sid, $langcode, $text) {
   $text = str_replace(array('<', '>'), array(' <', '> '), $text);
   $text = strip_tags($text, '<' . implode('><', array_keys($tags)) . '>');
 
-  // Remove diacitics.
-  $text = \Drupal::service('transliteration')->removeDiacritics($text);
-
   // Split HTML tags from plain text.
   $split = preg_split('/\s*<([^>]+?)>\s*/', $text, -1, PREG_SPLIT_DELIM_CAPTURE);
   // Note: PHP ensures the array consists of alternating delimiters and literals
diff --git a/core/tests/Drupal/Tests/Component/Transliteration/PhpTransliterationTest.php b/core/tests/Drupal/Tests/Component/Transliteration/PhpTransliterationTest.php
index 4da3bd4..f01ee05 100644
--- a/core/tests/Drupal/Tests/Component/Transliteration/PhpTransliterationTest.php
+++ b/core/tests/Drupal/Tests/Component/Transliteration/PhpTransliterationTest.php
@@ -26,14 +26,13 @@ class PhpTransliterationTest extends UnitTestCase {
    * @param string $original
    *   The language code to test.
    * @param string $expected
-   *  The expected return from PhpTransliteration::removeDiacritics().
+   *   The expected return from PhpTransliteration::removeDiacritics().
    *
    * @dataProvider providerTestPhpTransliterationRemoveDiacritics
    */
   public function testRemoveDiacritics($original, $expected) {
     $transliterator_class = new PhpTransliteration();
     $result = $transliterator_class->removeDiacritics($original);
-//    throw new \Exception($result);
     $this->assertEquals($expected, $result);
   }
 
@@ -46,7 +45,7 @@ public function testRemoveDiacritics($original, $expected) {
    */
   public function providerTestPhpTransliterationRemoveDiacritics() {
     return array(
-      // unicode range 0x00bf to 0x017f
+      // Test all characters in the Unicode range 0x00bf to 0x017f.
       array('ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏ', 'AAAAAAÆCEEEEIIII'),
       array('ÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞß', 'ÐNOOOOO×OUUUUYÞß'),
       array('àáâãäåæçèéêëìíîï', 'aaaaaaæceeeeiiii'),
@@ -60,7 +59,7 @@ public function providerTestPhpTransliterationRemoveDiacritics() {
       array('ŠšŢţŤťŦŧŨũŪūŬŭŮů', 'SsTtTtTtUuUuUuUu'),
       array('ŰűŲųŴŵŶŷŸŹźŻżŽž', 'UuUuWwYyYZzZzZz'),
 
-      // unicode range 01CD to 024F
+      // Test all characters in the Unicode range 0x01CD to 0x024F.
       array('ǍǎǏ', 'AaI'),
       array('ǐǑǒǓǔǕǖǗǘǙǚǛǜǝǞǟ', 'iOoUuUuUuUuUuǝAa'),
       array('ǠǡǢǣǤǥǦǧǨǩǪǫǬǭǮǯ', 'AaǢǣGgGgKkOoOoǮǯ'),