diff --git a/src/Wizard/FormWizardBase.php b/src/Wizard/FormWizardBase.php
index a9ded76..9332870 100644
--- a/src/Wizard/FormWizardBase.php
+++ b/src/Wizard/FormWizardBase.php
@@ -242,6 +242,12 @@ abstract class FormWizardBase extends FormBase implements FormWizardInterface {
    */
   public function buildForm(array $form, FormStateInterface $form_state) {
     $cached_values = $form_state->getTemporaryValue('wizard');
+    // Initialize cached values if they are empty.
+    if (empty($cached_values)) {
+      $cached_values = $this->initValues();
+      $form_state->setTemporaryValue('wizard', $cached_values);
+      $this->getTempStore()->set($this->getMachineName(), $cached_values);
+    }
     // Get the current form operation.
     $operation = $this->getOperation($cached_values);
     $form = $this->customizeForm($form, $form_state);