diff --git a/core/modules/workflows/src/Form/WorkflowStateAddForm.php b/core/modules/workflows/src/Form/WorkflowStateAddForm.php
index 1827dd3..7b55995 100644
--- a/core/modules/workflows/src/Form/WorkflowStateAddForm.php
+++ b/core/modules/workflows/src/Form/WorkflowStateAddForm.php
@@ -5,6 +5,7 @@
 use Drupal\Core\Entity\EntityForm;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\workflows\WorkflowTypeFormInterface;
 
 /**
  * Class WorkflowStateAddForm.
@@ -43,10 +44,13 @@ public function form(array $form, FormStateInterface $form_state) {
     ];
 
     // Add additional form fields from the workflow type plugin.
-    $form['type_settings'] = [
-      $workflow->get('type') => $workflow->getTypePlugin()->buildStateConfigurationForm($form_state, $workflow),
-      '#tree' => TRUE,
-    ];
+    $workflow_type = $workflow->getTypePlugin();
+    if ($workflow_type instanceof WorkflowTypeFormInterface) {
+      $form['type_settings'] = [
+        $workflow->get('type') => $workflow_type->buildStateConfigurationForm($form_state, $workflow),
+        '#tree' => TRUE,
+      ];
+    }
 
     return $form;
   }
diff --git a/core/modules/workflows/src/Form/WorkflowStateEditForm.php b/core/modules/workflows/src/Form/WorkflowStateEditForm.php
index f21508f..d87cb64 100644
--- a/core/modules/workflows/src/Form/WorkflowStateEditForm.php
+++ b/core/modules/workflows/src/Form/WorkflowStateEditForm.php
@@ -6,6 +6,7 @@
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Url;
+use Drupal\workflows\WorkflowTypeFormInterface;
 
 /**
  * Class WorkflowStateEditForm.
@@ -62,10 +63,13 @@ public function form(array $form, FormStateInterface $form_state) {
     ];
 
     // Add additional form fields from the workflow type plugin.
-    $form['type_settings'] = [
-      $workflow->get('type') => $workflow->getTypePlugin()->buildStateConfigurationForm($form_state, $workflow, $state),
-      '#tree' => TRUE,
-    ];
+    $workflow_type = $workflow->getTypePlugin();
+    if ($workflow_type instanceof WorkflowTypeFormInterface) {
+      $form['type_settings'] = [
+        $workflow->get('type') => $workflow_type->buildStateConfigurationForm($form_state, $workflow, $state),
+        '#tree' => TRUE,
+      ];
+    }
 
     $header = [
       'label' => $this->t('Transition'),
diff --git a/core/modules/workflows/src/Form/WorkflowTransitionAddForm.php b/core/modules/workflows/src/Form/WorkflowTransitionAddForm.php
index fe3a406..4761f58 100644
--- a/core/modules/workflows/src/Form/WorkflowTransitionAddForm.php
+++ b/core/modules/workflows/src/Form/WorkflowTransitionAddForm.php
@@ -6,6 +6,7 @@
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\workflows\State;
+use Drupal\workflows\WorkflowTypeFormInterface;
 
 /**
  * Class WorkflowTransitionAddForm.
@@ -62,10 +63,13 @@ public function form(array $form, FormStateInterface $form_state) {
     ];
 
     // Add additional form fields from the workflow type plugin.
-    $form['type_settings'] = [
-      $workflow->get('type') => $workflow->getTypePlugin()->buildTransitionConfigurationForm($form_state, $workflow),
-      '#tree' => TRUE,
-    ];
+    $workflow_type = $workflow->getTypePlugin();
+    if ($workflow_type instanceof WorkflowTypeFormInterface) {
+      $form['type_settings'] = [
+        $workflow->get('type') => $workflow_type->buildTransitionConfigurationForm($form_state, $workflow),
+        '#tree' => TRUE,
+      ];
+    }
 
     return $form;
   }
diff --git a/core/modules/workflows/src/Form/WorkflowTransitionEditForm.php b/core/modules/workflows/src/Form/WorkflowTransitionEditForm.php
index 5bbabae..1fbc0a2 100644
--- a/core/modules/workflows/src/Form/WorkflowTransitionEditForm.php
+++ b/core/modules/workflows/src/Form/WorkflowTransitionEditForm.php
@@ -7,6 +7,7 @@
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Url;
 use Drupal\workflows\State;
+use Drupal\workflows\WorkflowTypeFormInterface;
 
 /**
  * Class WorkflowTransitionEditForm.
@@ -78,10 +79,13 @@ public function form(array $form, FormStateInterface $form_state) {
     ];
 
     // Add additional form fields from the workflow type plugin.
-    $form['type_settings'] = [
-      $workflow->get('type') => $workflow->getTypePlugin()->buildTransitionConfigurationForm($form_state, $workflow, $transition),
-      '#tree' => TRUE,
-    ];
+    $workflow_type = $workflow->getTypePlugin();
+    if ($workflow_type instanceof WorkflowTypeFormInterface) {
+      $form['type_settings'] = [
+        $workflow->get('type') => $workflow_type->buildTransitionConfigurationForm($form_state, $workflow, $transition),
+        '#tree' => TRUE,
+      ];
+    }
 
     return $form;
   }
diff --git a/core/modules/workflows/src/Plugin/WorkflowTypeBase.php b/core/modules/workflows/src/Plugin/WorkflowTypeBase.php
index 34af735..66702d0 100644
--- a/core/modules/workflows/src/Plugin/WorkflowTypeBase.php
+++ b/core/modules/workflows/src/Plugin/WorkflowTypeBase.php
@@ -86,20 +86,6 @@ public function deleteTransition($transition_id) {
   /**
    * {@inheritdoc}
    */
-  public function buildStateConfigurationForm(FormStateInterface $form_state, WorkflowInterface $workflow, StateInterface $state = NULL) {
-    return [];
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function buildTransitionConfigurationForm(FormStateInterface $form_state, WorkflowInterface $workflow, TransitionInterface $transition = NULL) {
-    return [];
-  }
-
-  /**
-   * {@inheritdoc}
-   */
   public function getConfiguration() {
     return $this->configuration;
   }
diff --git a/core/modules/workflows/src/Plugin/WorkflowTypeFormBase.php b/core/modules/workflows/src/Plugin/WorkflowTypeFormBase.php
index 942c2d6..69f0e8c 100644
--- a/core/modules/workflows/src/Plugin/WorkflowTypeFormBase.php
+++ b/core/modules/workflows/src/Plugin/WorkflowTypeFormBase.php
@@ -3,6 +3,9 @@
 namespace Drupal\workflows\Plugin;
 
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\workflows\StateInterface;
+use Drupal\workflows\TransitionInterface;
+use Drupal\workflows\WorkflowInterface;
 use Drupal\workflows\WorkflowTypeFormInterface;
 
 /**
@@ -27,4 +30,18 @@ public function validateConfigurationForm(array &$form, FormStateInterface $form
   public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function buildStateConfigurationForm(FormStateInterface $form_state, WorkflowInterface $workflow, StateInterface $state = NULL) {
+    return [];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildTransitionConfigurationForm(FormStateInterface $form_state, WorkflowInterface $workflow, TransitionInterface $transition = NULL) {
+    return [];
+  }
+
 }
diff --git a/core/modules/workflows/src/WorkflowTypeFormInterface.php b/core/modules/workflows/src/WorkflowTypeFormInterface.php
index 7da4bd9..d5c957b 100644
--- a/core/modules/workflows/src/WorkflowTypeFormInterface.php
+++ b/core/modules/workflows/src/WorkflowTypeFormInterface.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\workflows;
 
+use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Plugin\PluginFormInterface;
 
 /**
@@ -13,4 +14,44 @@
  * @see plugin_api
  */
 interface WorkflowTypeFormInterface extends PluginFormInterface, WorkflowTypeInterface {
+
+  /**
+   * Builds a form to be added to the Workflow state edit form.
+   *
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The form state.
+   * @param \Drupal\workflows\WorkflowInterface $workflow
+   *   The workflow the state is attached to.
+   * @param \Drupal\workflows\StateInterface|null $state
+   *   The workflow state being edited. If NULL, a new state is being added.
+   *
+   * @return array
+   *   Form elements to add to a workflow state form for customisations to the
+   *   workflow.
+   *
+   * @see \Drupal\workflows\Form\WorkflowStateAddForm::form()
+   * @see \Drupal\workflows\Form\WorkflowStateEditForm::form()
+   */
+  public function buildStateConfigurationForm(FormStateInterface $form_state, WorkflowInterface $workflow, StateInterface $state = NULL);
+
+  /**
+   * Builds a form to be added to the Workflow transition edit form.
+   *
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The form state.
+   * @param \Drupal\workflows\WorkflowInterface $workflow
+   *   The workflow the state is attached to.
+   * @param \Drupal\workflows\TransitionInterface|null $transition
+   *   The workflow transition being edited. If NULL, a new transition is being
+   *   added.
+   *
+   * @return array
+   *   Form elements to add to a workflow transition form for customisations to
+   *   the workflow.
+   *
+   * @see \Drupal\workflows\Form\WorkflowTransitionAddForm::form()
+   * @see \Drupal\workflows\Form\WorkflowTransitionEditForm::form()
+   */
+  public function buildTransitionConfigurationForm(FormStateInterface $form_state, WorkflowInterface $workflow, TransitionInterface $transition = NULL);
+
 }
diff --git a/core/modules/workflows/src/WorkflowTypeInterface.php b/core/modules/workflows/src/WorkflowTypeInterface.php
index 2412bf9..7519cb1 100644
--- a/core/modules/workflows/src/WorkflowTypeInterface.php
+++ b/core/modules/workflows/src/WorkflowTypeInterface.php
@@ -105,45 +105,6 @@ public function deleteTransition($transition_id);
   public function getInitialState(WorkflowInterface $workflow);
 
   /**
-   * Builds a form to be added to the Workflow state edit form.
-   *
-   * @param \Drupal\Core\Form\FormStateInterface $form_state
-   *   The form state.
-   * @param \Drupal\workflows\WorkflowInterface $workflow
-   *   The workflow the state is attached to.
-   * @param \Drupal\workflows\StateInterface|null $state
-   *   The workflow state being edited. If NULL, a new state is being added.
-   *
-   * @return array
-   *   Form elements to add to a workflow state form for customisations to the
-   *   workflow.
-   *
-   * @see \Drupal\workflows\Form\WorkflowStateAddForm::form()
-   * @see \Drupal\workflows\Form\WorkflowStateEditForm::form()
-   */
-  public function buildStateConfigurationForm(FormStateInterface $form_state, WorkflowInterface $workflow, StateInterface $state = NULL);
-
-  /**
-   * Builds a form to be added to the Workflow transition edit form.
-   *
-   * @param \Drupal\Core\Form\FormStateInterface $form_state
-   *   The form state.
-   * @param \Drupal\workflows\WorkflowInterface $workflow
-   *   The workflow the state is attached to.
-   * @param \Drupal\workflows\TransitionInterface|null $transition
-   *   The workflow transition being edited. If NULL, a new transition is being
-   *   added.
-   *
-   * @return array
-   *   Form elements to add to a workflow transition form for customisations to
-   *   the workflow.
-   *
-   * @see \Drupal\workflows\Form\WorkflowTransitionAddForm::form()
-   * @see \Drupal\workflows\Form\WorkflowTransitionEditForm::form()
-   */
-  public function buildTransitionConfigurationForm(FormStateInterface $form_state, WorkflowInterface $workflow, TransitionInterface $transition = NULL);
-
-  /**
    * Gets the required states of workflow type.
    *
    * This are usually configured in the workflow type annotation.
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 2ff68a8..6b35266 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
@@ -2,6 +2,7 @@
 
 namespace Drupal\workflow_type_test\Plugin\WorkflowType;
 
+use Drupal\Core\Form\FormStateInterface;
 use Drupal\workflows\Plugin\WorkflowTypeBase;
 
 /**