diff --git a/core/modules/workflows/tests/modules/workflow_type_test/src/Plugin/WorkflowType/TestType.php b/core/modules/workflows/tests/modules/workflow_type_test/src/Plugin/WorkflowType/TestType.php
index ddd074a..26dc42f 100644
--- a/core/modules/workflows/tests/modules/workflow_type_test/src/Plugin/WorkflowType/TestType.php
+++ b/core/modules/workflows/tests/modules/workflow_type_test/src/Plugin/WorkflowType/TestType.php
@@ -3,6 +3,7 @@
 namespace Drupal\workflow_type_test\Plugin\WorkflowType;
 
 use Drupal\workflows\Plugin\WorkflowTypeBase;
+use Drupal\workflows\WorkflowInterface;
 
 /**
  * Test workflow type.
@@ -17,6 +18,13 @@ class TestType extends WorkflowTypeBase {
   /**
    * {@inheritdoc}
    */
+  public function workflowHasData(WorkflowInterface $workflow) {
+    return \Drupal::state()->get('workflow_type_test.has_data', FALSE);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function getRequiredStates() {
     // Normally this is obtained from the annotation but we get from state to
     // allow dynamic testing.
diff --git a/core/modules/workflows/tests/src/Kernel/WorkflowDependenciesTest.php b/core/modules/workflows/tests/src/Kernel/WorkflowDependenciesTest.php
index c1070dc..75efcc7 100644
--- a/core/modules/workflows/tests/src/Kernel/WorkflowDependenciesTest.php
+++ b/core/modules/workflows/tests/src/Kernel/WorkflowDependenciesTest.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\workflows\Kernel;
 
+use Drupal\Core\Extension\ModuleUninstallValidatorException;
 use Drupal\KernelTests\KernelTestBase;
 use Drupal\workflows\Entity\Workflow;
 
@@ -38,4 +39,43 @@ public function testOnDependencyRemoval() {
     $this->assertSame(['workflow_type_test'], $workflow->getDependencies()['module']);
   }
 
+  /**
+   * Test uninstalling a module that provides a workflow type.
+   *
+   * @covers \Drupal\workflows\WorkflowsUninstallValidator::validate
+   */
+  public function testUninstallModuleWithWorkflowTypeInUse() {
+    $module_installer = \Drupal::service('module_installer');
+
+    // Create a workflow of a type for which we can control whether it is in use
+    // or not.
+    $workflow = Workflow::create([
+      'type' => 'workflow_type_test',
+      'id' => 'test_workflow',
+    ]);
+    $workflow->save();
+
+    // Simulate a workflow type that is in use.
+    \Drupal::state()->set('workflow_type_test.has_data', TRUE);
+
+    try {
+      $module_installer->uninstall(['workflow_type_test']);
+      $this->fail('A module that provides a workflow type that is in use can not be uninstalled.');
+    }
+    catch (ModuleUninstallValidatorException $e) {
+      $this->assertTrue(TRUE,'A module that provides a workflow type that is in use can not be uninstalled.');
+    }
+
+    // Simulate a workflow type that is no longer being used.
+    \Drupal::state()->set('workflow_type_test.has_data', FALSE);
+    try {
+      $module_installer->uninstall(['workflow_type_test']);
+      $this->assertTrue(TRUE,'A module that provides a workflow type that is not in use can be uninstalled.');
+
+    }
+    catch (ModuleUninstallValidatorException $e) {
+      $this->fail('A module that provides a workflow type that is not in use can be uninstalled.');
+    }
+  }
+
 }