diff --git a/core/tests/Drupal/Tests/Component/Utility/UnicodeTest.php b/core/tests/Drupal/Tests/Component/Utility/UnicodeTest.php
index fc3c3c4..3409c5e 100644
--- a/core/tests/Drupal/Tests/Component/Utility/UnicodeTest.php
+++ b/core/tests/Drupal/Tests/Component/Utility/UnicodeTest.php
@@ -49,9 +49,7 @@ public function providerTestMimeHeader() {
    * @covers ::strtolower
    * @covers ::caseFlip
    */
-  public function testStrtolower($text, $expected, $multibyte = FALSE) {
-    $status = $multibyte ? Unicode::STATUS_MULTIBYTE : Unicode::STATUS_SINGLEBYTE;
-    Unicode::setStatus($status);
+  public function testStrtolower($text, $expected) {
     $this->assertEquals($expected, Unicode::strtolower($text));
   }
 
@@ -61,22 +59,14 @@ public function testStrtolower($text, $expected, $multibyte = FALSE) {
    * @see testStrtolower()
    *
    * @return array
-   *   An array containing a string, its lowercase version and whether it should
-   *   be processed as multibyte.
+   *   An array containing a string and its lowercase version.
    */
   public function providerStrtolower() {
-    $cases = array(
+    return array(
       array('tHe QUIcK bRoWn', 'the quick brown'),
       array('FrançAIS is ÜBER-åwesome', 'français is über-åwesome'),
+      array('ΑΒΓΔΕΖΗΘΙΚΛΜΝΞΟΣὨ', 'αβγδεζηθικλμνξοσὠ', TRUE),
     );
-    foreach ($cases as $case) {
-      // Test the same string both in multibyte and singlebyte conditions.
-      array_push($case, TRUE);
-      $cases[] = $case;
-    }
-    // Add a multibyte string.
-    $cases[] = array('ΑΒΓΔΕΖΗΘΙΚΛΜΝΞΟΣὨ', 'αβγδεζηθικλμνξοσὠ', TRUE);
-    return $cases;
   }
 
   /**
@@ -86,9 +76,7 @@ public function providerStrtolower() {
    * @covers ::strtoupper
    * @covers ::caseFlip
    */
-  public function testStrtoupper($text, $expected, $multibyte = FALSE) {
-    $status = $multibyte ? Unicode::STATUS_MULTIBYTE : Unicode::STATUS_SINGLEBYTE;
-    Unicode::setStatus($status);
+  public function testStrtoupper($text, $expected) {
     $this->assertEquals($expected, Unicode::strtoupper($text));
   }
 
@@ -98,22 +86,14 @@ public function testStrtoupper($text, $expected, $multibyte = FALSE) {
    * @see testStrtoupper()
    *
    * @return array
-   *   An array containing a string, its uppercase version and whether it should
-   *   be processed as multibyte.
+   *   An array containing a string and its uppercase version.
    */
   public function providerStrtoupper() {
-    $cases = array(
+    return array(
       array('tHe QUIcK bRoWn', 'THE QUICK BROWN'),
       array('FrançAIS is ÜBER-åwesome', 'FRANÇAIS IS ÜBER-ÅWESOME'),
+      array('αβγδεζηθικλμνξοσὠ', 'ΑΒΓΔΕΖΗΘΙΚΛΜΝΞΟΣὨ'),
     );
-    foreach ($cases as $case) {
-      // Test the same string both in multibyte and singlebyte conditions.
-      array_push($case, TRUE);
-      $cases[] = $case;
-    }
-    // Add a multibyte string.
-    $cases[] = array('αβγδεζηθικλμνξοσὠ', 'ΑΒΓΔΕΖΗΘΙΚΛΜΝΞΟΣὨ', TRUE);
-    return $cases;
   }
 
   /**
@@ -151,9 +131,7 @@ public function providerUcfirst() {
    * @dataProvider providerLcfirst
    * @covers ::lcfirst
    */
-  public function testLcfirst($text, $expected, $multibyte = FALSE) {
-    $status = $multibyte ? Unicode::STATUS_MULTIBYTE : Unicode::STATUS_SINGLEBYTE;
-    Unicode::setStatus($status);
+  public function testLcfirst($text, $expected) {
     $this->assertEquals($expected, Unicode::lcfirst($text));
   }
 
@@ -163,8 +141,7 @@ public function testLcfirst($text, $expected, $multibyte = FALSE) {
    * @see testLcfirst()
    *
    * @return array
-   *   An array containing a string, its lowercase version and whether it should
-   *   be processed as multibyte.
+   *   An array containing a string and its lowercase version.
    */
   public function providerLcfirst() {
     return array(
@@ -173,7 +150,7 @@ public function providerLcfirst() {
       array('Über', 'über'),
       array('Åwesome', 'åwesome'),
       // Add a multibyte string.
-      array('ΑΒΓΔΕΖΗΘΙΚΛΜΝΞΟΣὨ', 'αΒΓΔΕΖΗΘΙΚΛΜΝΞΟΣὨ', TRUE),
+      array('ΑΒΓΔΕΖΗΘΙΚΛΜΝΞΟΣὨ', 'αΒΓΔΕΖΗΘΙΚΛΜΝΞΟΣὨ'),
     );
   }
 
@@ -184,8 +161,6 @@ public function providerLcfirst() {
    * @covers ::ucwords
    */
   public function testUcwords($text, $expected, $multibyte = FALSE) {
-    $status = $multibyte ? Unicode::STATUS_MULTIBYTE : Unicode::STATUS_SINGLEBYTE;
-    Unicode::setStatus($status);
     $this->assertEquals($expected, Unicode::ucwords($text));
   }
 
@@ -195,8 +170,7 @@ public function testUcwords($text, $expected, $multibyte = FALSE) {
    * @see testUcwords()
    *
    * @return array
-   *   An array containing a string, its capitalized version and whether it should
-   *   be processed as multibyte.
+   *   An array containing a string and its capitalized version.
    */
   public function providerUcwords() {
     return array(
@@ -207,7 +181,7 @@ public function providerUcwords() {
       // Make sure we don't mangle extra spaces.
       array('frànçAIS is  über-åwesome', 'FrànçAIS Is  Über-Åwesome'),
       // Add a multibyte string.
-      array('σion', 'Σion', TRUE),
+      array('σion', 'Σion'),
     );
   }
 
@@ -218,11 +192,6 @@ public function providerUcwords() {
    * @covers ::strlen
    */
   public function testStrlen($text, $expected) {
-    // Run through multibyte code path.
-    Unicode::setStatus(Unicode::STATUS_MULTIBYTE);
-    $this->assertEquals($expected, Unicode::strlen($text));
-    // Run through singlebyte code path.
-    Unicode::setStatus(Unicode::STATUS_SINGLEBYTE);
     $this->assertEquals($expected, Unicode::strlen($text));
   }
 
@@ -249,11 +218,6 @@ public function providerStrlen() {
    * @covers ::substr
    */
   public function testSubstr($text, $start, $length, $expected) {
-    // Run through multibyte code path.
-    Unicode::setStatus(Unicode::STATUS_MULTIBYTE);
-    $this->assertEquals($expected, Unicode::substr($text, $start, $length));
-    // Run through singlebyte code path.
-    Unicode::setStatus(Unicode::STATUS_SINGLEBYTE);
     $this->assertEquals($expected, Unicode::substr($text, $start, $length));
   }
 
@@ -484,11 +448,6 @@ public function providerTestConvertToUtf8() {
    * @covers ::strpos
    */
   public function testStrpos($haystack, $needle, $offset, $expected) {
-    // Run through multibyte code path.
-    Unicode::setStatus(Unicode::STATUS_MULTIBYTE);
-    $this->assertEquals($expected, Unicode::strpos($haystack, $needle, $offset));
-    // Run through singlebyte code path.
-    Unicode::setStatus(Unicode::STATUS_SINGLEBYTE);
     $this->assertEquals($expected, Unicode::strpos($haystack, $needle, $offset));
   }