diff --git a/composer.json b/composer.json
index 3b2817124d8494aa44cc59483dfebc06d0ea256f..0d6ef8c505044153f1493fc57c1ebf67504ee07e 100644
--- a/composer.json
+++ b/composer.json
@@ -2,6 +2,7 @@
   "name": "drupal/mailchimp_transactional",
   "type": "drupal-module",
   "require": {
-    "mailchimp/transactional": "^1.0.47"
+    "mailchimp/transactional": "^1.0.47",
+    "drupal/mailsystem": "^4"
   }
 }
diff --git a/mailchimp_transactional.info.yml b/mailchimp_transactional.info.yml
index 5105b66b52e49dd9ce08531f3f963ea71a6a14b7..de2077b5d1345eb67ef842db8064866b54c112fd 100644
--- a/mailchimp_transactional.info.yml
+++ b/mailchimp_transactional.info.yml
@@ -2,7 +2,7 @@ name: Mailchimp Transactional
 type: module
 description: 'Allow for site emails to be sent through Mailchimp Transactional.'
 package: Mailchimp Transactional
-core_version_requirement: ^9
+core_version_requirement: ^9 || ^10
 
 configure: mailchimp_transactional.admin
 
diff --git a/modules/mailchimp_transactional_activity/mailchimp_transactional_activity.info.yml b/modules/mailchimp_transactional_activity/mailchimp_transactional_activity.info.yml
index ad3283f6d6ed8ded616e1b0e53a04b400ed07ad4..e069a8b419debb072c4106ee7d344cc553551690 100644
--- a/modules/mailchimp_transactional_activity/mailchimp_transactional_activity.info.yml
+++ b/modules/mailchimp_transactional_activity/mailchimp_transactional_activity.info.yml
@@ -1,7 +1,7 @@
 name: 'Mailchimp Transactional Activity'
 description: 'View Mailchimp Transactional activity for any entity with an email address.'
 package: Mailchimp Transactional
-core_version_requirement: ^8 || ^9
+core_version_requirement: ^9 || ^10
 dependencies:
   - mailchimp_transactional:mailchimp_transactional
 type: module
diff --git a/modules/mailchimp_transactional_activity/src/Form/ActivityForm.php b/modules/mailchimp_transactional_activity/src/Form/ActivityForm.php
index 6bb867bc0215aa45ca228f7732db6c82ab209a5a..b4326123ccfcf47e8704e04ab8e59c12d0aedce8 100644
--- a/modules/mailchimp_transactional_activity/src/Form/ActivityForm.php
+++ b/modules/mailchimp_transactional_activity/src/Form/ActivityForm.php
@@ -224,6 +224,7 @@ class ActivityForm extends EntityForm {
       $entity = $this->entityTypeManager->getStorage('mailchimp_transactional_activity')->getQuery()
         ->condition('entity_type', $form_state->getValue('entity_type'))
         ->condition('bundle', $form_state->getValue('bundle'))
+        ->accessCheck(TRUE)
         ->execute();
 
       if (!empty($entity)) {
@@ -257,6 +258,7 @@ class ActivityForm extends EntityForm {
   public function exists($id) {
     $entity = $this->entityTypeManager->getStorage('mailchimp_transactional_activity')->getQuery()
       ->condition('id', $id)
+      ->accessCheck(TRUE)
       ->execute();
     return (bool) $entity;
   }
diff --git a/modules/mailchimp_transactional_reports/mailchimp_transactional_reports.info.yml b/modules/mailchimp_transactional_reports/mailchimp_transactional_reports.info.yml
index f3404cd61a89b26d14c49556de4e75d4ed470a1c..5cf46ab743c981fc3f81942741db6ac9c5a9e143 100644
--- a/modules/mailchimp_transactional_reports/mailchimp_transactional_reports.info.yml
+++ b/modules/mailchimp_transactional_reports/mailchimp_transactional_reports.info.yml
@@ -1,7 +1,6 @@
 name: 'Mailchimp Transactional Reports'
 description: 'Providing reporting on activity through Mailchimp Transactional.'
-core: 8.x
-core_version_requirement: ^8 || ^9
+core_version_requirement: ^9 || ^10
 package: Mailchimp Transactional
 dependencies:
   - mailchimp_transactional:mailchimp_transactional
diff --git a/modules/mailchimp_transactional_template/mailchimp_transactional_template.info.yml b/modules/mailchimp_transactional_template/mailchimp_transactional_template.info.yml
index 0d8d8828e2e7c452af9c221760144f876cac30ef..f5d3cd7e9e1590c622b3a9f39ac57002c8e7a9a5 100644
--- a/modules/mailchimp_transactional_template/mailchimp_transactional_template.info.yml
+++ b/modules/mailchimp_transactional_template/mailchimp_transactional_template.info.yml
@@ -1,6 +1,6 @@
 name: 'Mailchimp Transactional Templates'
 description: 'Use Mailchimp Transactional templates for messages sent with Mailchimp Transactional.'
-core_version_requirement: ^8 || ^9
+core_version_requirement: ^9 || ^10
 package: Mailchimp Transactional
 dependencies:
   - mailchimp_transactional:mailchimp_transactional
diff --git a/modules/mailchimp_transactional_template/src/Form/TemplateMapForm.php b/modules/mailchimp_transactional_template/src/Form/TemplateMapForm.php
index 05c01590578bdd4f342a8944079df6189509a87a..dbdd091a38f391777dd6077f8f5101e2ff64a752 100644
--- a/modules/mailchimp_transactional_template/src/Form/TemplateMapForm.php
+++ b/modules/mailchimp_transactional_template/src/Form/TemplateMapForm.php
@@ -215,6 +215,7 @@ class TemplateMapForm extends EntityForm {
   public function exists($id): bool {
     $entity = $this->entityTypeManager->getStorage('mailchimp_transactional_template')->getQuery()
       ->condition('id', $id)
+      ->accessCheck(TRUE)
       ->execute();
     return (bool) $entity;
   }