diff --git a/core/tests/Drupal/Tests/PhpunitCompatibilityTrait.php b/core/tests/Drupal/Tests/PhpunitCompatibilityTrait.php
index b82022f6ab..5cf020a8df 100644
--- a/core/tests/Drupal/Tests/PhpunitCompatibilityTrait.php
+++ b/core/tests/Drupal/Tests/PhpunitCompatibilityTrait.php
@@ -10,7 +10,7 @@
   /**
    * Returns a mock object for the specified class using the available method.
    *
-   * The getMock method is does not exist in PHPUnit 6. To provide backward
+   * The getMock method does not exist in PHPUnit 6. To provide backward
    * compatibility this trait provides the getMock method and uses createMock if
    * this method is available on the parent class.
    *
diff --git a/core/tests/Drupal/Tests/PhpunitCompatibilityTraitTest.php b/core/tests/Drupal/Tests/PhpunitCompatibilityTraitTest.php
index f512b9d060..c6281e48e2 100644
--- a/core/tests/Drupal/Tests/PhpunitCompatibilityTraitTest.php
+++ b/core/tests/Drupal/Tests/PhpunitCompatibilityTraitTest.php
@@ -60,7 +60,7 @@ public function getMock($originalClassName) {
 }
 
 /**
- * Test class for \PHPUnit\Framework\TestCase in PHPUnit 5.
+ * Test class for \PHPUnit\Framework\TestCase in PHPUnit 6.
  */
 class Phpunit6TestClass {
   public function createMock($originalClassName) {
@@ -99,7 +99,7 @@ class UnitTestCasePhpunit4TestClassExtends extends UnitTestCasePhpunit4TestClass
 }
 
 /**
- * Test class for \Drupal\Tests\UnitTestCase with PHPUnit 5.
+ * Test class for \Drupal\Tests\UnitTestCase with PHPUnit 6.
  */
 class UnitTestCasePhpunit6TestClass extends Phpunit6TestClass {
   use PhpunitCompatibilityTrait;
@@ -107,7 +107,7 @@ class UnitTestCasePhpunit6TestClass extends Phpunit6TestClass {
 }
 
 /**
- * Test class for \Drupal\Tests\UnitTestCase with PHPUnit 5.
+ * Test class for \Drupal\Tests\UnitTestCase with PHPUnit 6.
  */
 class UnitTestCasePhpunit6TestClassExtends extends UnitTestCasePhpunit6TestClass {
 }