diff --git a/core/lib/Drupal/Component/Datetime/DateTimePlus.php b/core/lib/Drupal/Component/Datetime/DateTimePlus.php
index 3495314..ee9a26e 100644
--- a/core/lib/Drupal/Component/Datetime/DateTimePlus.php
+++ b/core/lib/Drupal/Component/Datetime/DateTimePlus.php
@@ -314,7 +314,16 @@ public function __call($method, $args) {
     if (!method_exists($this->dateTimeObject, $method)) {
       throw new \BadMethodCallException(sprintf('Call to undefined method %s::%s()', get_class($this), $method));
     }
-    return call_user_func_array([$this->dateTimeObject, $method], $args);
+
+    $val = call_user_func_array([$this->dateTimeObject, $method], $args);
+
+    if (is_object($val) && get_class($val) === 'DateTime') {
+      $this->dateTimeObject = $val;
+      return $this;
+    }
+    else {
+      return $val;
+    }
   }
 
   /**
diff --git a/core/tests/Drupal/Tests/Component/Datetime/DateTimePlusTest.php b/core/tests/Drupal/Tests/Component/Datetime/DateTimePlusTest.php
index 2becc97..1a350e0 100644
--- a/core/tests/Drupal/Tests/Component/Datetime/DateTimePlusTest.php
+++ b/core/tests/Drupal/Tests/Component/Datetime/DateTimePlusTest.php
@@ -804,4 +804,45 @@ public function testValidateFormat() {
     $date = DateTimePlus::createFromFormat('Y-m-d H:i:s', '11-03-31 17:44:00', 'UTC', ['validate_format' => TRUE]);
   }
 
+  /**
+   * Tests that object methods are chainable.
+   *
+   * @covers ::__call
+   */
+  public function testChainable() {
+    $date = new DateTimePlus('now', 'Australia/Sydney');
+
+    $date->setTimestamp(12345678);
+    $rendered = $date->render();
+    $this->assertEquals('1970-05-24 07:21:18 Australia/Sydney', $rendered);
+
+    $date->setTimestamp(23456789);
+    $rendered = $date->setTimezone(new \DateTimeZone('America/New_York'))->render();
+    $this->assertEquals('1970-09-29 07:46:29 America/New_York', $rendered);
+  }
+
+  /**
+   * Tests that non-chainable methods work.
+   *
+   * @covers ::__call
+   */
+  public function testChainableNonChainable() {
+    $datetime1 = new DateTimePlus('2009-10-11 12:00:00');
+    $datetime2 = new DateTimePlus('2009-10-13 12:00:00');
+    $interval = $datetime1->diff($datetime2);
+    $this->assertInstanceOf(\DateInterval::class, $interval);
+    $this->assertEquals('+2 days', $interval->format('%R%a days'));
+  }
+
+  /**
+   * Tests that chained calls to non-existent functions throw an exception.
+   *
+   * @covers ::__call
+   */
+  public function testChainableNonCallable() {
+    $this->setExpectedException(\BadMethodCallException::class, 'Call to undefined method Drupal\Component\Datetime\DateTimePlus::nonexistent()');
+    $date = new DateTimePlus('now', 'Australia/Sydney');
+    $date->setTimezone(new \DateTimeZone('America/New_York'))->nonexistent();
+  }
+
 }
diff --git a/core/tests/Drupal/Tests/Core/Datetime/DrupalDateTimeTest.php b/core/tests/Drupal/Tests/Core/Datetime/DrupalDateTimeTest.php
index eff9f77..096d99d 100644
--- a/core/tests/Drupal/Tests/Core/Datetime/DrupalDateTimeTest.php
+++ b/core/tests/Drupal/Tests/Core/Datetime/DrupalDateTimeTest.php
@@ -156,4 +156,48 @@ public function providerTestInvalidDateDiff() {
     ];
   }
 
+  /**
+   * Tests that object methods are chainable.
+   *
+   * @covers ::__call
+   */
+  public function testChainable() {
+    $tz = new \DateTimeZone(date_default_timezone_get());
+    $date = new DrupalDateTime('now', $tz, ['langcode' => 'en']);
+
+    $date->setTimestamp(12345678);
+    $rendered = $date->render();
+    $this->assertEquals('1970-05-24 07:21:18 Australia/Sydney', $rendered);
+
+    $date->setTimestamp(23456789);
+    $rendered = $date->setTimezone(new \DateTimeZone('America/New_York'))->render();
+    $this->assertEquals('1970-09-29 07:46:29 America/New_York', $rendered);
+  }
+
+  /**
+   * Tests that non-chainable methods work.
+   *
+   * @covers ::__call
+   */
+  public function testChainableNonChainable() {
+    $tz = new \DateTimeZone(date_default_timezone_get());
+    $datetime1 = new DrupalDateTime('2009-10-11 12:00:00', $tz, ['langcode' => 'en']);
+    $datetime2 = new DrupalDateTime('2009-10-13 12:00:00', $tz, ['langcode' => 'en']);
+    $interval = $datetime1->diff($datetime2);
+    $this->assertInstanceOf(\DateInterval::class, $interval);
+    $this->assertEquals('+2 days', $interval->format('%R%a days'));
+  }
+
+  /**
+   * Tests that chained calls to non-existent functions throw an exception.
+   *
+   * @covers ::__call
+   */
+  public function testChainableNonCallable() {
+    $this->setExpectedException(\BadMethodCallException::class, 'Call to undefined method Drupal\Core\Datetime\DrupalDateTime::nonexistent()');
+    $tz = new \DateTimeZone(date_default_timezone_get());
+    $date = new DrupalDateTime('now', $tz, ['langcode' => 'en']);
+    $date->setTimezone(new \DateTimeZone('America/New_York'))->nonexistent();
+  }
+
 }