core/modules/block/src/BlockForm.php | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/core/modules/block/src/BlockForm.php b/core/modules/block/src/BlockForm.php
index 8c13bbb..8144663 100644
--- a/core/modules/block/src/BlockForm.php
+++ b/core/modules/block/src/BlockForm.php
@@ -8,6 +8,7 @@
 namespace Drupal\block;
 
 use Drupal\Component\Utility\Html;
+use Drupal\Core\Block\MainContentBlockPluginInterface;
 use Drupal\Core\Entity\EntityForm;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Executable\ExecutableManagerInterface;
@@ -127,6 +128,9 @@ public function form(array $form, FormStateInterface $form_state) {
     $form['#tree'] = TRUE;
     $form['settings'] = $entity->getPlugin()->buildConfigurationForm(array(), $form_state);
     $form['visibility'] = $this->buildVisibilityInterface([], $form_state);
+    if ($entity->getPlugin() instanceof MainContentBlockPluginInterface) {
+      $form['visibility']['#access'] = FALSE;
+    }
 
     // If creating a new block, calculate a safe default machine name.
     $form['id'] = array(