diff --git a/islandora_citations.info.yml b/islandora_citations.info.yml
index 09de850..47f2714 100644
--- a/islandora_citations.info.yml
+++ b/islandora_citations.info.yml
@@ -2,7 +2,7 @@ name: Islandora citations
 type: module
 description: Provides a service to manage citations.
 package: Custom
-core_version_requirement: ^9
+core_version_requirement: ^10
 dependencies:
   - drupal:field_permissions
   - drupal:node
diff --git a/src/Controller/IslandoraCitationsController.php b/src/Controller/IslandoraCitationsController.php
index 47bd7ba..2576628 100644
--- a/src/Controller/IslandoraCitationsController.php
+++ b/src/Controller/IslandoraCitationsController.php
@@ -50,6 +50,7 @@ public function provideArguments($node_type) {
     ];
     $fields = $this->entityFieldManager->getFieldDefinitions('node', $node_type);
 
+    $rows = [];
     foreach ($fields as $field_definition) {
 
       if (!empty($field_definition->getTargetBundle())) {
@@ -93,6 +94,7 @@ public function paragraphsArguments($paragraphs_type) {
     ];
     $fields = $this->entityFieldManager->getFieldDefinitions('paragraph', $paragraphs_type->id());
 
+    $rows = [];
     foreach ($fields as $field_definition) {
       if (!empty($field_definition->getTargetBundle())) {
         $data = $field_definition->getThirdPartySetting('islandora_citations', 'csl_field');
diff --git a/src/Normalizer/DateTimeNormalizer.php b/src/Normalizer/DateTimeNormalizer.php
index ffc5ed5..1c96e6f 100644
--- a/src/Normalizer/DateTimeNormalizer.php
+++ b/src/Normalizer/DateTimeNormalizer.php
@@ -57,9 +57,13 @@ public function normalize($datetime, $format = NULL, array $context = []) {
     assert($datetime instanceof DateTimeInterface);
     $drupal_date_time = $datetime->getDateTime()->setTimezone($this->getNormalizationTimezone());
     if ($drupal_date_time === NULL) {
-      return $drupal_date_time;
+      return NULL;
     }
+
     $date = $this->dateFormatter->format($drupal_date_time->getTimestamp(), 'custom', 'Y-m-d');
+
+    $element = [];
+
     foreach ($context['csl-map'] as $cslField) {
       $element[$cslField] = $date;
     }
diff --git a/src/Normalizer/NormalizerBase.php b/src/Normalizer/NormalizerBase.php
index 0e3b9a8..42e83d3 100644
--- a/src/Normalizer/NormalizerBase.php
+++ b/src/Normalizer/NormalizerBase.php
@@ -18,8 +18,8 @@ abstract class NormalizerBase extends SerializationNormalizerBase implements Nor
   /**
    * {@inheritdoc}
    */
-  public function supportsNormalization($data, $format = NULL) {
-    return $format === static::FORMAT && parent::supportsNormalization($data, $format);
+  public function supportsNormalization($data, ?string $format = NULL, array $context = []): bool {
+    return $format === static::FORMAT && parent::supportsNormalization($data, $format, $context);
   }
 
   /**