diff --git a/src/assertions.rst b/src/assertions.rst
index 9df8a5051..50929c28d 100644
--- a/src/assertions.rst
+++ b/src/assertions.rst
@@ -2452,14 +2452,14 @@ assertThat()
 ############
 
 More complex assertions can be formulated using the
-``PHPUnit_Framework_Constraint`` classes. They can be
+``PHPUnit\Framework\Constraint`` classes. They can be
 evaluated using the ``assertThat()`` method.
 :numref:`appendixes.assertions.assertThat.example` shows how the
 ``logicalNot()`` and ``equalTo()``
 constraints can be used to express the same assertion as
 ``assertNotEquals()``.
 
-``assertThat(mixed $value, PHPUnit_Framework_Constraint $constraint[, $message = ''])``
+``assertThat(mixed $value, PHPUnit\Framework\Constraint $constraint[, $message = ''])``
 
 Reports an error identified by ``$message`` if the ``$value`` does not match the ``$constraint``.
 
@@ -2488,7 +2488,7 @@ Reports an error identified by ``$message`` if the ``$value`` does not match the
     ?>
 
 :numref:`appendixes.assertions.assertThat.tables.constraints` shows the
-available ``PHPUnit_Framework_Constraint`` classes.
+available ``PHPUnit\Framework\Constraint`` classes.
 
 .. rst-class:: table
 .. list-table:: Constraints
@@ -2497,71 +2497,71 @@ available ``PHPUnit_Framework_Constraint`` classes.
 
     * - Constraint
       - Meaning
-    * - ``PHPUnit_Framework_Constraint_Attribute attribute(PHPUnit_Framework_Constraint $constraint, $attributeName)``
+    * - ``PHPUnit\Framework\Constraint\Attribute attribute(PHPUnit\Framework\Constraint $constraint, $attributeName)``
       - Constraint that applies another constraint to an attribute of a class or an object.
-    * - ``PHPUnit_Framework_Constraint_IsAnything anything()``
+    * - ``PHPUnit\Framework\Constraint\IsAnything anything()``
       - Constraint that accepts any input value.
-    * - ``PHPUnit_Framework_Constraint_ArrayHasKey arrayHasKey(mixed $key)``
+    * - ``PHPUnit\Framework\Constraint\ArrayHasKey arrayHasKey(mixed $key)``
       - Constraint that asserts that the array it is evaluated for has a given key.
-    * - ``PHPUnit_Framework_Constraint_TraversableContains contains(mixed $value)``
+    * - ``PHPUnit\Framework\Constraint\TraversableContains contains(mixed $value)``
       - Constraint that asserts that the ``array`` or object that implements the ``Iterator`` interface it is evaluated for contains a given value.
-    * - ``PHPUnit_Framework_Constraint_TraversableContainsOnly containsOnly(string $type)``
+    * - ``PHPUnit\Framework\Constraint\TraversableContainsOnly containsOnly(string $type)``
       - Constraint that asserts that the ``array`` or object that implements the ``Iterator`` interface it is evaluated for contains only values of a given type.
-    * - ``PHPUnit_Framework_Constraint_TraversableContainsOnly containsOnlyInstancesOf(string $classname)``
+    * - ``PHPUnit\Framework\Constraint\TraversableContainsOnly containsOnlyInstancesOf(string $classname)``
       - Constraint that asserts that the ``array`` or object that implements the ``Iterator`` interface it is evaluated for contains only instances of a given classname.
-    * - ``PHPUnit_Framework_Constraint_IsEqual equalTo($value, $delta = 0, $maxDepth = 10)``
+    * - ``PHPUnit\Framework\Constraint\IsEqual equalTo($value, $delta = 0, $maxDepth = 10)``
       - Constraint that checks if one value is equal to another.
-    * - ``PHPUnit_Framework_Constraint_Attribute attributeEqualTo($attributeName, $value, $delta = 0, $maxDepth = 10)``
+    * - ``PHPUnit\Framework\Constraint\Attribute attributeEqualTo($attributeName, $value, $delta = 0, $maxDepth = 10)``
       - Constraint that checks if a value is equal to an attribute of a class or of an object.
-    * - ``PHPUnit_Framework_Constraint_DirectoryExists directoryExists()``
+    * - ``PHPUnit\Framework\Constraint\DirectoryExists directoryExists()``
       - Constraint that checks if the directory that it is evaluated for exists.
-    * - ``PHPUnit_Framework_Constraint_FileExists fileExists()``
+    * - ``PHPUnit\Framework\Constraint\FileExists fileExists()``
       - Constraint that checks if the file(name) that it is evaluated for exists.
-    * - ``PHPUnit_Framework_Constraint_IsReadable isReadable()``
+    * - ``PHPUnit\Framework\Constraint\IsReadable isReadable()``
       - Constraint that checks if the file(name) that it is evaluated for is readable.
-    * - ``PHPUnit_Framework_Constraint_IsWritable isWritable()``
+    * - ``PHPUnit\Framework\Constraint\IsWritable isWritable()``
       - Constraint that checks if the file(name) that it is evaluated for is writable.
-    * - ``PHPUnit_Framework_Constraint_GreaterThan greaterThan(mixed $value)``
+    * - ``PHPUnit\Framework\Constraint\GreaterThan greaterThan(mixed $value)``
       - Constraint that asserts that the value it is evaluated for is greater than a given value.
-    * - ``PHPUnit_Framework_Constraint_Or greaterThanOrEqual(mixed $value)``
+    * - ``PHPUnit\Framework\Constraint\Or greaterThanOrEqual(mixed $value)``
       - Constraint that asserts that the value it is evaluated for is greater than or equal to a given value.
-    * - ``PHPUnit_Framework_Constraint_ClassHasAttribute classHasAttribute(string $attributeName)``
+    * - ``PHPUnit\Framework\Constraint\ClassHasAttribute classHasAttribute(string $attributeName)``
       - Constraint that asserts that the class it is evaluated for has a given attribute.
-    * - ``PHPUnit_Framework_Constraint_ClassHasStaticAttribute classHasStaticAttribute(string $attributeName)``
+    * - ``PHPUnit\Framework\Constraint\ClassHasStaticAttribute classHasStaticAttribute(string $attributeName)``
       - Constraint that asserts that the class it is evaluated for has a given static attribute.
-    * - ``PHPUnit_Framework_Constraint_ObjectHasAttribute hasAttribute(string $attributeName)``
+    * - ``PHPUnit\Framework\Constraint\ObjectHasAttribute hasAttribute(string $attributeName)``
       - Constraint that asserts that the object it is evaluated for has a given attribute.
-    * - ``PHPUnit_Framework_Constraint_IsIdentical identicalTo(mixed $value)``
+    * - ``PHPUnit\Framework\Constraint\IsIdentical identicalTo(mixed $value)``
       - Constraint that asserts that one value is identical to another.
-    * - ``PHPUnit_Framework_Constraint_IsFalse isFalse()``
+    * - ``PHPUnit\Framework\Constraint\IsFalse isFalse()``
       - Constraint that asserts that the value it is evaluated is ``false``.
-    * - ``PHPUnit_Framework_Constraint_IsInstanceOf isInstanceOf(string $className)``
+    * - ``PHPUnit\Framework\Constraint\IsInstanceOf isInstanceOf(string $className)``
       - Constraint that asserts that the object it is evaluated for is an instance of a given class.
-    * - ``PHPUnit_Framework_Constraint_IsNull isNull()``
+    * - ``PHPUnit\Framework\Constraint\IsNull isNull()``
       - Constraint that asserts that the value it is evaluated is ``null``.
-    * - ``PHPUnit_Framework_Constraint_IsTrue isTrue()``
+    * - ``PHPUnit\Framework\Constraint\IsTrue isTrue()``
       - Constraint that asserts that the value it is evaluated is ``true``.
-    * - ``PHPUnit_Framework_Constraint_IsType isType(string $type)``
+    * - ``PHPUnit\Framework\Constraint\IsType isType(string $type)``
       - Constraint that asserts that the value it is evaluated for is of a specified type.
-    * - ``PHPUnit_Framework_Constraint_LessThan lessThan(mixed $value)``
+    * - ``PHPUnit\Framework\Constraint\LessThan lessThan(mixed $value)``
       - Constraint that asserts that the value it is evaluated for is smaller than a given value.
-    * - ``PHPUnit_Framework_Constraint_Or lessThanOrEqual(mixed $value)``
+    * - ``PHPUnit\Framework\Constraint\Or lessThanOrEqual(mixed $value)``
       - Constraint that asserts that the value it is evaluated for is smaller than or equal to a given value.
     * - ``logicalAnd()``
       - Logical AND.
-    * - ``logicalNot(PHPUnit_Framework_Constraint $constraint)``
+    * - ``logicalNot(PHPUnit\Framework\Constraint $constraint)``
       - Logical NOT.
     * - ``logicalOr()``
       - Logical OR.
     * - ``logicalXor()``
       - Logical XOR.
-    * - ``PHPUnit_Framework_Constraint_PCREMatch matchesRegularExpression(string $pattern)``
+    * - ``PHPUnit\Framework\Constraint\PCREMatch matchesRegularExpression(string $pattern)``
       - Constraint that asserts that the string it is evaluated for matches a regular expression.
-    * - ``PHPUnit_Framework_Constraint_StringContains stringContains(string $string, bool $case)``
+    * - ``PHPUnit\Framework\Constraint\StringContains stringContains(string $string, bool $case)``
       - Constraint that asserts that the string it is evaluated for contains a given string.
-    * - ``PHPUnit_Framework_Constraint_StringEndsWith stringEndsWith(string $suffix)``
+    * - ``PHPUnit\Framework\Constraint\StringEndsWith stringEndsWith(string $suffix)``
       - Constraint that asserts that the string it is evaluated for ends with a given suffix.
-    * - ``PHPUnit_Framework_Constraint_StringStartsWith stringStartsWith(string $prefix)``
+    * - ``PHPUnit\Framework\Constraint\StringStartsWith stringStartsWith(string $prefix)``
       - Constraint that asserts that the string it is evaluated for starts with a given prefix.
 
 .. _appendixes.assertions.assertTrue:
diff --git a/src/code-coverage-analysis.rst b/src/code-coverage-analysis.rst
index 6765afcde..54f89c9d2 100644
--- a/src/code-coverage-analysis.rst
+++ b/src/code-coverage-analysis.rst
@@ -283,9 +283,9 @@ generate code coverage with unit tests.
     :name: code-coverage-analysis.specifying-covered-methods.examples.GuestbookIntegrationTest.php
 
     <?php
-    use PHPUnit\Framework\TestCase;
+    use PHPUnit\DbUnit\TestCase
 
-    class GuestbookIntegrationTest extends PHPUnit_Extensions_Database_TestCase
+    class GuestbookIntegrationTest extends TestCase
     {
         /**
          * @coversNothing
diff --git a/src/configuration.rst b/src/configuration.rst
index 6b228ac60..77be9a27c 100644
--- a/src/configuration.rst
+++ b/src/configuration.rst
@@ -29,7 +29,7 @@ be used to configure PHPUnit's core functionality.
              convertWarningsToExceptions="true"
              forceCoversAnnotation="false"
              mapTestClassNameToCoveredClassName="false"
-             printerClass="PHPUnit_TextUI_ResultPrinter"
+             printerClass="PHPUnit\TextUI\ResultPrinter"
              <!--printerFile="/path/to/ResultPrinter.php"-->
              processIsolation="false"
              stopOnError="false"
@@ -37,7 +37,7 @@ be used to configure PHPUnit's core functionality.
              stopOnIncomplete="false"
              stopOnSkipped="false"
              stopOnRisky="false"
-             testSuiteLoaderClass="PHPUnit_Runner_StandardTestSuiteLoader"
+             testSuiteLoaderClass="PHPUnit\Runner\StandardTestSuiteLoader"
              <!--testSuiteLoaderFile="/path/to/StandardTestSuiteLoader.php"-->
              timeoutForSmallTests="1"
              timeoutForMediumTests="10"
diff --git a/src/database.rst b/src/database.rst
index a28c70ad6..8660e1a54 100644
--- a/src/database.rst
+++ b/src/database.rst
@@ -228,7 +228,7 @@ abstract TestCase requiring you to implement two abstract methods
         use TestCaseTrait;
 
         /**
-         * @return PHPUnit_Extensions_Database_DB_IDatabaseConnection
+         * @return PHPUnit\DbUnit\Database\Connection
          */
         public function getConnection()
         {
@@ -237,7 +237,7 @@ abstract TestCase requiring you to implement two abstract methods
         }
 
         /**
-         * @return PHPUnit_Extensions_Database_DataSet_IDataSet
+         * @return PHPUnit\DbUnit\DataSet\IDataSet
          */
         public function getDataSet()
         {
@@ -263,7 +263,7 @@ and pass it to the ``createDefaultDBConnection``
 method which wraps the PDO instance and the second parameter (the
 database-name) in a very simple abstraction layer for database
 connections of the type
-``PHPUnit_Extensions_Database_DB_IDatabaseConnection``.
+``PHPUnit\DbUnit\Database\Connection``.
 
 The section “Using the Database Connection API“ explains
 the API of this interface and how you can make the best use of it.
@@ -278,8 +278,8 @@ state of the database should look before each test is
 executed. The state of a database is abstracted through the
 concepts DataSet and DataTable both being represented by the
 interfaces
-``PHPUnit_Extensions_Database_DataSet_IDataSet`` and
-``PHPUnit_Extensions_Database_DataSet_IDataTable``.
+``PHPUnit\DbUnit\DataSet\IDataSet`` and
+``PHPUnit\DbUnit\DataSet\IDataTable``.
 The next section will describe in detail how these concepts work
 and what the benefits are for using them in database testing.
 
@@ -345,7 +345,7 @@ different data-fixture for each test case:
         // only instantiate pdo once for test clean-up/fixture load
         static private $pdo = null;
 
-        // only instantiate PHPUnit_Extensions_Database_DB_IDatabaseConnection once per test
+        // only instantiate PHPUnit\DbUnit\Database\Connection once per test
         private $conn = null;
 
         final public function getConnection()
@@ -397,7 +397,7 @@ We can now modify our test-case to look like:
         // only instantiate pdo once for test clean-up/fixture load
         static private $pdo = null;
 
-        // only instantiate PHPUnit_Extensions_Database_DB_IDatabaseConnection once per test
+        // only instantiate PHPUnit\DbUnit\Database\Connection once per test
         private $conn = null;
 
         final public function getConnection()
@@ -877,7 +877,13 @@ straightforward:
 .. code-block:: php
 
     <?php
-    class MyApp_DbUnit_ArrayDataSet extends PHPUnit_Extensions_Database_DataSet_AbstractDataSet
+
+    use PHPUnit\DbUnit\DataSet\AbstractDataSet;
+    use PHPUnit\DbUnit\DataSet\DefaultTableMetaData
+    use PHPUnit\DbUnit\DataSet\DefaultTable
+    use PHPUnit\DbUnit\DataSet\DefaultTableIterator
+
+    class MyApp_DbUnit_ArrayDataSet extends AbstractDataSet
     {
         /**
          * @var array
@@ -895,8 +901,8 @@ straightforward:
                     $columns = array_keys($rows[0]);
                 }
 
-                $metaData = new PHPUnit_Extensions_Database_DataSet_DefaultTableMetaData($tableName, $columns);
-                $table = new PHPUnit_Extensions_Database_DataSet_DefaultTable($metaData);
+                $metaData = new DefaultTableMetaData($tableName, $columns);
+                $table = new DefaultTable($metaData);
 
                 foreach ($rows AS $row) {
                     $table->addRow($row);
@@ -907,7 +913,7 @@ straightforward:
 
         protected function createIterator($reverse = false)
         {
-            return new PHPUnit_Extensions_Database_DataSet_DefaultTableIterator($this->tables, $reverse);
+            return new DefaultTableIterator($this->tables, $reverse);
         }
 
         public function getTable($tableName)
@@ -933,7 +939,7 @@ contents of the database. This is where the Query DataSet shines:
 .. code-block:: php
 
     <?php
-    $ds = new PHPUnit_Extensions_Database_DataSet_QueryDataSet($this->getConnection());
+    $ds = new PHPUnit\DbUnit\DataSet\QueryDataSet($this->getConnection());
     $ds->addTable('guestbook');
     ?>
 
@@ -943,7 +949,7 @@ data-table with the following query:
 .. code-block:: php
 
     <?php
-    $ds = new PHPUnit_Extensions_Database_DataSet_QueryDataSet($this->getConnection());
+    $ds = new PHPUnit\DbUnit\DataSet\QueryDataSet($this->getConnection());
     $ds->addTable('guestbook', 'SELECT * FROM guestbook');
     ?>
 
@@ -954,7 +960,7 @@ tables, for example restricting rows, column or adding
 .. code-block:: php
 
     <?php
-    $ds = new PHPUnit_Extensions_Database_DataSet_QueryDataSet($this->getConnection());
+    $ds = new PHPUnit\DbUnit\DataSet\QueryDataSet($this->getConnection());
     $ds->addTable('guestbook', 'SELECT id, content FROM guestbook ORDER BY created DESC');
     ?>
 
@@ -987,7 +993,7 @@ specified table names with a whitelist as shown in
         use TestCaseTrait;
 
         /**
-         * @return PHPUnit_Extensions_Database_DB_IDatabaseConnection
+         * @return PHPUnit\DbUnit\Database\Connection
          */
         public function getConnection()
         {
@@ -1050,7 +1056,7 @@ We then wrap the Flat XML DataSet into a Replacement DataSet:
         public function getDataSet()
         {
             $ds = $this->createFlatXmlDataSet('myFlatXmlFixture.xml');
-            $rds = new PHPUnit_Extensions_Database_DataSet_ReplacementDataSet($ds);
+            $rds = new PHPUnit\DbUnit\DataSet\ReplacementDataSet($ds);
             $rds->addFullReplacement('##NULL##', null);
             return $rds;
         }
@@ -1082,7 +1088,7 @@ with the DB DataSet to filter the columns of the datasets.
             $tableNames = ['guestbook'];
             $dataSet = $this->getConnection()->createDataSet();
 
-            $filterDataSet = new PHPUnit_Extensions_Database_DataSet_DataSetFilter($dataSet);
+            $filterDataSet = new PHPUnit\DbUnit\DataSet\DataSetFilter($dataSet);
             $filterDataSet->addIncludeTables(['guestbook']);
             $filterDataSet->setIncludeColumnsForTable('guestbook', ['id', 'content']);
             // ..
@@ -1093,14 +1099,14 @@ with the DB DataSet to filter the columns of the datasets.
             $tableNames = ['guestbook'];
             $dataSet = $this->getConnection()->createDataSet();
 
-            $filterDataSet = new PHPUnit_Extensions_Database_DataSet_DataSetFilter($dataSet);
+            $filterDataSet = new PHPUnit\DbUnit\DataSet\DataSetFilter($dataSet);
             $filterDataSet->addExcludeTables(['foo', 'bar', 'baz']); // only keep the guestbook table!
             $filterDataSet->setExcludeColumnsForTable('guestbook', ['user', 'created']);
             // ..
         }
     }
     ?>
-    
+
 .. admonition:: Note
 
     You cannot use both exclude and include column filtering on the same table,
@@ -1151,7 +1157,7 @@ Using the Composite DataSet we can aggregate both fixture files:
             $ds1 = $this->createFlatXmlDataSet('fixture1.xml');
             $ds2 = $this->createFlatXmlDataSet('fixture2.xml');
 
-            $compositeDs = new PHPUnit_Extensions_Database_DataSet_CompositeDataSet();
+            $compositeDs = new PHPUnit\DbUnit\DataSet\CompositeDataSet();
             $compositeDs->addDataSet($ds1);
             $compositeDs->addDataSet($ds2);
 
@@ -1183,12 +1189,14 @@ do not plan to implement your own DataSet or DataTable.
 .. code-block:: php
 
     <?php
-    interface PHPUnit_Extensions_Database_DataSet_IDataSet extends IteratorAggregate
+    namespace PHPUnit\DbUnit\DataSet;
+
+    interface IDataSet extends IteratorAggregate
     {
         public function getTableNames();
         public function getTableMetaData($tableName);
         public function getTable($tableName);
-        public function assertEquals(PHPUnit_Extensions_Database_DataSet_IDataSet $other);
+        public function assertEquals(IDataSet $other);
 
         public function getReverseIterator();
     }
@@ -1214,13 +1222,15 @@ A table is also represented by the following interface:
 .. code-block:: php
 
     <?php
-    interface PHPUnit_Extensions_Database_DataSet_ITable
+    namespace PHPUnit\DbUnit\DataSet;
+
+    interface ITable
     {
         public function getTableMetaData();
         public function getRowCount();
         public function getValue($row, $column);
         public function getRow($row);
-        public function assertEquals(PHPUnit_Extensions_Database_DataSet_ITable $other);
+        public function assertEquals(ITable $other);
     }
     ?>
 
@@ -1230,7 +1240,7 @@ the different assertions of the Database Extension that are
 explained in the next chapter. The
 ``getTableMetaData()`` method has to return an
 implementation of the
-``PHPUnit_Extensions_Database_DataSet_ITableMetaData``
+``PHPUnit\DbUnit\DataSet\ITableMetaData``
 interface, which describes the structure of the table. It holds
 information on:
 
@@ -1263,7 +1273,9 @@ which has to be returned from the
 .. code-block:: php
 
     <?php
-    interface PHPUnit_Extensions_Database_DB_IDatabaseConnection
+    namespace PHPUnit\DbUnit\Database;
+
+    interface Connection
     {
         public function createDataSet(Array $tableNames = NULL);
         public function createQueryTable($resultName, $sql);
@@ -1543,6 +1555,7 @@ different ways for DataSet assertions.
        <?php
        use PHPUnit\Framework\TestCase;
        use PHPUnit\DbUnit\TestCaseTrait;
+       use PHPUnit\DbUnit\DataSet\QueryDataSet;
 
        class DataSetAssertionsTest extends TestCase
        {
@@ -1550,7 +1563,7 @@ different ways for DataSet assertions.
 
            public function testManualDataSetAssertion()
            {
-               $dataSet = new PHPUnit_Extensions_Database_DataSet_QueryDataSet();
+               $dataSet = new QueryDataSet();
                $dataSet->addTable('guestbook', 'SELECT id, content, user FROM guestbook'); // additional tables
                $expectedDataSet = $this->createFlatXmlDataSet('guestbook.xml');
 
diff --git a/src/extending-phpunit.rst b/src/extending-phpunit.rst
index 8209eed11..ecf31c50c 100644
--- a/src/extending-phpunit.rst
+++ b/src/extending-phpunit.rst
@@ -34,13 +34,15 @@ PHPUnit's own assertions are implemented. As you can see in
 ``assertThat()`` for evaluation.
 
 .. code-block:: php
-    :caption: The assertTrue() and isTrue() methods of the PHPUnit_Framework_Assert class
+    :caption: The assertTrue() and isTrue() methods of the PHPUnit\Framework\Assert class
     :name: extending-phpunit.examples.Assert.php
 
     <?php
+    namespace PHPUnit\Framework;
+
     use PHPUnit\Framework\TestCase;
 
-    abstract class PHPUnit_Framework_Assert
+    abstract class Assert
     {
         // ...
 
@@ -49,7 +51,7 @@ PHPUnit's own assertions are implemented. As you can see in
          *
          * @param  boolean $condition
          * @param  string  $message
-         * @throws PHPUnit_Framework_AssertionFailedError
+         * @throws PHPUnit\Framework\AssertionFailedError
          */
         public static function assertTrue($condition, $message = '')
         {
@@ -59,32 +61,34 @@ PHPUnit's own assertions are implemented. As you can see in
         // ...
 
         /**
-         * Returns a PHPUnit_Framework_Constraint_IsTrue matcher object.
+         * Returns a PHPUnit\Framework\Constraint\IsTrue matcher object.
          *
-         * @return PHPUnit_Framework_Constraint_IsTrue
+         * @return PHPUnit\Framework\Constraint\IsTrue
          * @since  Method available since Release 3.3.0
          */
         public static function isTrue()
         {
-            return new PHPUnit_Framework_Constraint_IsTrue;
+            return new PHPUnit\Framework\Constraint\IsTrue;
         }
 
         // ...
     }?>
 
 :numref:`extending-phpunit.examples.IsTrue.php` shows how
-``PHPUnit_Framework_Constraint_IsTrue`` extends the
+``PHPUnit\Framework\Constraint\IsTrue`` extends the
 abstract base class for matcher objects (or constraints),
-``PHPUnit_Framework_Constraint``.
+``PHPUnit\Framework\Constraint``.
 
 .. code-block:: php
-    :caption: The PHPUnit_Framework_Constraint_IsTrue class
+    :caption: The PHPUnit\Framework\Constraint\IsTrue class
     :name: extending-phpunit.examples.IsTrue.php
 
     <?php
-    use PHPUnit\Framework\TestCase;
+    namespace PHPUnit\Framework\Constraint;
 
-    class PHPUnit_Framework_Constraint_IsTrue extends PHPUnit_Framework_Constraint
+    use PHPUnit\Framework\Constraint;
+
+    class IsTrue extends Constraint
     {
         /**
          * Evaluates the constraint for parameter $other. Returns true if the
@@ -111,7 +115,7 @@ abstract base class for matcher objects (or constraints),
 
 The effort of implementing the ``assertTrue()`` and
 ``isTrue()`` methods as well as the
-``PHPUnit_Framework_Constraint_IsTrue`` class yields the
+``PHPUnit\Framework\Constraint\IsTrue`` class yields the
 benefit that ``assertThat()`` automatically takes care of
 evaluating the assertion and bookkeeping tasks such as counting it for
 statistics. Furthermore, the ``isTrue()`` method can be
@@ -136,47 +140,47 @@ interface.
 
     class SimpleTestListener implements TestListener
     {
-        public function addError(PHPUnit_Framework_Test $test, Exception $e, $time)
+        public function addError(PHPUnit\Framework\Test $test, Exception $e, $time)
         {
             printf("Error while running test '%s'.\n", $test->getName());
         }
 
-        public function addFailure(PHPUnit_Framework_Test $test, PHPUnit_Framework_AssertionFailedError $e, $time)
+        public function addFailure(PHPUnit\Framework\Test $test, PHPUnit\Framework\AssertionFailedError $e, $time)
         {
             printf("Test '%s' failed.\n", $test->getName());
         }
 
-        public function addIncompleteTest(PHPUnit_Framework_Test $test, Exception $e, $time)
+        public function addIncompleteTest(PHPUnit\Framework\Test $test, Exception $e, $time)
         {
             printf("Test '%s' is incomplete.\n", $test->getName());
         }
 
-        public function addRiskyTest(PHPUnit_Framework_Test $test, Exception $e, $time)
+        public function addRiskyTest(PHPUnit\Framework\Test $test, Exception $e, $time)
         {
             printf("Test '%s' is deemed risky.\n", $test->getName());
         }
 
-        public function addSkippedTest(PHPUnit_Framework_Test $test, Exception $e, $time)
+        public function addSkippedTest(PHPUnit\Framework\Test $test, Exception $e, $time)
         {
             printf("Test '%s' has been skipped.\n", $test->getName());
         }
 
-        public function startTest(PHPUnit_Framework_Test $test)
+        public function startTest(PHPUnit\Framework\Test $test)
         {
             printf("Test '%s' started.\n", $test->getName());
         }
 
-        public function endTest(PHPUnit_Framework_Test $test, $time)
+        public function endTest(PHPUnit\Framework\Test $test, $time)
         {
             printf("Test '%s' ended.\n", $test->getName());
         }
 
-        public function startTestSuite(PHPUnit_Framework_TestSuite $suite)
+        public function startTestSuite(PHPUnit\Framework\TestSuite $suite)
         {
             printf("TestSuite '%s' started.\n", $suite->getName());
         }
 
-        public function endTestSuite(PHPUnit_Framework_TestSuite $suite)
+        public function endTestSuite(PHPUnit\Framework\TestSuite $suite)
         {
             printf("TestSuite '%s' ended.\n", $suite->getName());
         }
@@ -184,7 +188,7 @@ interface.
     ?>
 
 :numref:`extending-phpunit.examples.BaseTestListener.php`
-shows how to subclass the ``PHPUnit_Framework_BaseTestListener``
+shows how to subclass the ``PHPUnit\Framework\BaseTestListener``
 abstract class, which lets you specify only the interface methods that
 are interesting for your use case, while providing empty implementations
 for all the others.
@@ -194,11 +198,11 @@ for all the others.
     :name: extending-phpunit.examples.BaseTestListener.php
 
     <?php
-    use PHPUnit\Framework\TestCase;
+    use PHPUnit\Framework\BaseTestListener;
 
-    class ShortTestListener extends PHPUnit_Framework_BaseTestListener
+    class ShortTestListener extends BaseTestListener
     {
-        public function endTest(PHPUnit_Framework_Test $test, $time)
+        public function endTest(PHPUnit\Framework\Test $test, $time)
         {
             printf("Test '%s' ended.\n", $test->getName());
         }
@@ -241,7 +245,7 @@ test decorator that illustrates how to write your own test decorators.
     {
         private $timesRepeat = 1;
 
-        public function __construct(PHPUnit_Framework_Test $test, $timesRepeat = 1)
+        public function __construct(PHPUnit\Framework\Test $test, $timesRepeat = 1)
         {
             parent::__construct($test);
 
@@ -256,7 +260,7 @@ test decorator that illustrates how to write your own test decorators.
             return $this->timesRepeat * $this->test->count();
         }
 
-        public function run(PHPUnit_Framework_TestResult $result = null)
+        public function run(PHPUnit\Framework\TestResult $result = null)
         {
             if ($result === null) {
                 $result = $this->createResult();
@@ -273,12 +277,12 @@ test decorator that illustrates how to write your own test decorators.
 
 .. _extending-phpunit.PHPUnit_Framework_Test:
 
-Implement PHPUnit_Framework_Test
+Implement PHPUnit\Framework\Test
 ################################
 
-The ``PHPUnit_Framework_Test`` interface is narrow and
+The ``PHPUnit\Framework\Test`` interface is narrow and
 easy to implement. You can write an implementation of
-``PHPUnit_Framework_Test`` that is simpler than
+``PHPUnit\Framework\Test`` that is simpler than
 ``PHPUnit\Framework\TestCase`` and that runs
 *data-driven tests*, for instance.
 
@@ -295,7 +299,7 @@ and the second value is the actual one.
     <?php
     use PHPUnit\Framework\TestCase;
 
-    class DataDrivenTest implements PHPUnit_Framework_Test
+    class DataDrivenTest implements PHPUnit\Framework\Test
     {
         private $lines;
 
@@ -309,10 +313,10 @@ and the second value is the actual one.
             return 1;
         }
 
-        public function run(PHPUnit_Framework_TestResult $result = null)
+        public function run(PHPUnit\Framework\TestResult $result = null)
         {
             if ($result === null) {
-                $result = new PHPUnit_Framework_TestResult;
+                $result = new PHPUnit\Framework\TestResult;
             }
 
             foreach ($this->lines as $line) {
@@ -323,12 +327,12 @@ and the second value is the actual one.
                 list($expected, $actual) = explode(';', $line);
 
                 try {
-                    PHPUnit_Framework_Assert::assertEquals(
+                    PHPUnit\Framework\Assert::assertEquals(
                       trim($expected), trim($actual)
                     );
                 }
 
-                catch (PHPUnit_Framework_AssertionFailedError $e) {
+                catch (PHPUnit\Framework\AssertionFailedError $e) {
                     $stopTime = PHP_Timer::stop();
                     $result->addFailure($this, $e, $stopTime);
                 }
@@ -350,7 +354,7 @@ and the second value is the actual one.
     }
 
     $test = new DataDrivenTest('data_file.csv');
-    $result = PHPUnit_TextUI_TestRunner::run($test);
+    $result = PHPUnit\TextUI\TestRunner::run($test);
     ?>
 
 .. code-block:: bash
diff --git a/src/incomplete-and-skipped-tests.rst b/src/incomplete-and-skipped-tests.rst
index 2ff157539..0bf4f010c 100644
--- a/src/incomplete-and-skipped-tests.rst
+++ b/src/incomplete-and-skipped-tests.rst
@@ -33,17 +33,17 @@ test as a success.
 If we think of a successful test as a green light and a test failure
 as a red light, we need an additional yellow light to mark a test
 as being incomplete or not yet implemented.
-``PHPUnit_Framework_IncompleteTest`` is a marker
+``PHPUnit\Framework\IncompleteTest`` is a marker
 interface for marking an exception that is raised by a test method as
 the result of the test being incomplete or currently not implemented.
-``PHPUnit_Framework_IncompleteTestError`` is the
+``PHPUnit\Framework\IncompleteTestError`` is the
 standard implementation of this interface.
 
 :numref:`incomplete-and-skipped-tests.incomplete-tests.examples.SampleTest.php`
 shows a test case class, ``SampleTest``, that contains one test
 method, ``testSomething()``. By calling the convenience
 method ``markTestIncomplete()`` (which automatically
-raises an ``PHPUnit_Framework_IncompleteTestError``
+raises an ``PHPUnit\Framework\IncompleteTestError``
 exception) in the test method, we mark the test as being incomplete.
 
 .. code-block:: php
diff --git a/src/logging.rst b/src/logging.rst
index 774f4702c..0c93bf065 100644
--- a/src/logging.rst
+++ b/src/logging.rst
@@ -66,7 +66,7 @@ shows how failures and errors are denoted.
                   line="6"
                   assertions="1"
                   time="0.011456">
-          <failure type="PHPUnit_Framework_ExpectationFailedException">
+          <failure type="PHPUnit\Framework\ExpectationFailedException">
     testFailure(FailureErrorTest)
     Failed asserting that &lt;integer:2&gt; matches expected value &lt;integer:1&gt;.
 
diff --git a/src/test-doubles.rst b/src/test-doubles.rst
index d298fe120..dfd363cec 100644
--- a/src/test-doubles.rst
+++ b/src/test-doubles.rst
@@ -706,17 +706,17 @@ invocations.
 
     * - Matcher
       - Meaning
-    * - ``PHPUnit_Framework_MockObject_Matcher_AnyInvokedCount any()``
+    * - ``PHPUnit\Framework\MockObject\Matcher\AnyInvokedCount any()``
       - Returns a matcher that matches when the method it is evaluated for is executed zero or more times.
-    * - ``PHPUnit_Framework_MockObject_Matcher_InvokedCount never()``
+    * - ``PHPUnit\Framework\MockObject\Matcher\InvokedCount never()``
       - Returns a matcher that matches when the method it is evaluated for is never executed.
-    * - ``PHPUnit_Framework_MockObject_Matcher_InvokedAtLeastOnce atLeastOnce()``
+    * - ``PHPUnit\Framework\MockObject\Matcher\InvokedAtLeastOnce atLeastOnce()``
       - Returns a matcher that matches when the method it is evaluated for is executed at least once.
-    * - ``PHPUnit_Framework_MockObject_Matcher_InvokedCount once()``
+    * - ``PHPUnit\Framework\MockObject\Matcher\InvokedCount once()``
       - Returns a matcher that matches when the method it is evaluated for is executed exactly once.
-    * - ``PHPUnit_Framework_MockObject_Matcher_InvokedCount exactly(int $count)``
+    * - ``PHPUnit\Framework\MockObject\Matcher\InvokedCount exactly(int $count)``
       - Returns a matcher that matches when the method it is evaluated for is executed exactly ``$count`` times.
-    * - ``PHPUnit_Framework_MockObject_Matcher_InvokedAtIndex at(int $index)``
+    * - ``PHPUnit\Framework\MockObject\Matcher\InvokedAtIndex at(int $index)``
       - Returns a matcher that matches when the method it is evaluated for is invoked at the given ``$index``.
 
 .. admonition:: Note
diff --git a/src/textui.rst b/src/textui.rst
index e4484f07d..c3b5e0ff3 100644
--- a/src/textui.rst
+++ b/src/textui.rst
@@ -176,9 +176,9 @@ the following code:
     ``UnitTest`` must be either a class that inherits
     from ``PHPUnit\Framework\TestCase`` or a class that
     provides a ``public static suite()`` method which
-    returns a ``PHPUnit_Framework_Test`` object, for
+    returns a ``PHPUnit\Framework\Test`` object, for
     example an instance of the
-    ``PHPUnit_Framework_TestSuite`` class.
+    ``PHPUnit\Framework\TestSuite`` class.
 
 ``phpunit UnitTest UnitTest.php``
 
@@ -443,7 +443,7 @@ the following code:
 
 ``--loader``
 
-    Specifies the ``PHPUnit_Runner_TestSuiteLoader``
+    Specifies the ``PHPUnit\Runner\TestSuiteLoader``
     implementation to use.
 
     The standard test suite loader will look for the sourcefile in the
@@ -465,7 +465,7 @@ the following code:
 ``--printer``
 
     Specifies the result printer to use. The printer class must extend
-    ``PHPUnit_Util_Printer`` and implement the
+    ``PHPUnit\Util\Printer`` and implement the
     ``PHPUnit\Framework\TestListener`` interface.
 
 ``--bootstrap``