core/lib/Drupal/Core/Config/Schema/SequenceDataDefinition.php | 7 +++++++
 core/tests/Drupal/KernelTests/Config/TypedConfigTest.php      | 4 ++++
 2 files changed, 11 insertions(+)

diff --git a/core/lib/Drupal/Core/Config/Schema/SequenceDataDefinition.php b/core/lib/Drupal/Core/Config/Schema/SequenceDataDefinition.php
index c616741a5c..ca8dec7590 100644
--- a/core/lib/Drupal/Core/Config/Schema/SequenceDataDefinition.php
+++ b/core/lib/Drupal/Core/Config/Schema/SequenceDataDefinition.php
@@ -25,4 +25,11 @@ public function getOrderBy() {
     return $this->definition['orderby'] ?? NULL;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function getDataType() {
+    return 'sequence';
+  }
+
 }
diff --git a/core/tests/Drupal/KernelTests/Config/TypedConfigTest.php b/core/tests/Drupal/KernelTests/Config/TypedConfigTest.php
index adba8b8e0b..5dc3762654 100644
--- a/core/tests/Drupal/KernelTests/Config/TypedConfigTest.php
+++ b/core/tests/Drupal/KernelTests/Config/TypedConfigTest.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\KernelTests\Config;
 
+use Drupal\Core\Config\Schema\Sequence;
 use Drupal\Core\Config\Schema\SequenceDataDefinition;
 use Drupal\Core\Config\Schema\TypedConfigInterface;
 use Drupal\Core\TypedData\ComplexDataDefinitionInterface;
@@ -73,6 +74,9 @@ public function testTypedDataAPI() {
     // Test accessing sequences.
     $sequence = $typed_config->get('giraffe');
     /** @var \Drupal\Core\TypedData\ListInterface $sequence */
+    $this->assertInstanceOf(SequenceDataDefinition::class, $sequence->getDataDefinition());
+    $this->assertSame(Sequence::class, $sequence->getDataDefinition()->getClass());
+    $this->assertSame('sequence', $sequence->getDataDefinition()->getDataType());
     $this->assertInstanceOf(ComplexDataInterface::class, $sequence);
     $this->assertInstanceOf(StringInterface::class, $sequence->get('hum1'));
     $this->assertEquals('hum1', $sequence->get('hum1')->getValue());