diff --git a/src/Form/SelectCslForm.php b/src/Form/SelectCslForm.php
index a1d395b..21d9771 100644
--- a/src/Form/SelectCslForm.php
+++ b/src/Form/SelectCslForm.php
@@ -112,7 +112,7 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       if (isset($settings['id'])) {
         if ($settings['id'] == 'islandora_citations_display_citations') {
           $default_csl = !empty($settings['default_csl']) ? $settings['default_csl'] : array_values($cslItems)[0];
-          $this->blockCSLType = $settings['default_csl_type'];
+          $this->blockCSLType = $settings['default_csl_type'] ?? "";
         }
       }
     }