diff --git forkSrcPrefix/src/Plugin/DevelGenerate/WebformSubmissionDevelGenerate.php forkDstPrefix/src/Plugin/DevelGenerate/WebformSubmissionDevelGenerate.php
index 1c72b0fe5f19e6b08ed049c163038d8dc02b5aa0..03aa56569b74eb369b3537a48931157e1871ff9c 100644
--- forkSrcPrefix/src/Plugin/DevelGenerate/WebformSubmissionDevelGenerate.php
+++ forkDstPrefix/src/Plugin/DevelGenerate/WebformSubmissionDevelGenerate.php
@@ -224,7 +224,7 @@ class WebformSubmissionDevelGenerate extends DevelGenerateBase implements Contai
    * @param array $values
    *   The element values from the settings webform.
    */
-  protected function generateSubmissions(array $values): array {
+  protected function generateSubmissions(array $values): void {
     static::$generatingSubmissions = TRUE;
     if (!empty($values['kill'])) {
       $this->deleteWebformSubmissions($values['webform_ids'], $values['entity-type'], $values['entity-id']);