diff --git a/core/modules/block_content/block_content.module b/core/modules/block_content/block_content.module
index 98f0925ab9..5248e811ad 100644
--- a/core/modules/block_content/block_content.module
+++ b/core/modules/block_content/block_content.module
@@ -11,6 +11,7 @@
 use Drupal\Core\Database\Query\SelectInterface;
 use Drupal\Core\Database\Query\AlterableInterface;
 use Drupal\Core\Database\Query\ConditionInterface;
+use Drupal\block_content\Plugin\EntityReferenceSelection\BlockContentSelection;
 
 /**
  * Implements hook_help().
@@ -127,6 +128,12 @@ function block_content_add_body_field($block_type_id, $label = 'Body') {
  * @see \Drupal\block_content\BlockContentAccessControlHandler
  */
 function block_content_query_entity_reference_alter(AlterableInterface $query) {
+  if (!empty($query->alterMetaData["entity_reference_selection_handler"]) && $query->alterMetaData["entity_reference_selection_handler"] instanceof BlockContentSelection) {
+    // The entity reference selection plugin module provided by this module
+    // already filters out non-reusable blocks so now altering of the query is
+    // needed.
+    return;
+  }
   if ($query instanceof SelectInterface && $query->getMetaData('entity_type') === 'block_content' && $query->hasTag('block_content_access')) {
     $data_table = \Drupal::entityTypeManager()->getDefinition('block_content')->getDataTable();
     if (array_key_exists($data_table, $query->getTables()) && !_block_content_has_reusable_condition($query->conditions(), $query->getTables())) {
diff --git a/core/modules/block_content/src/Plugin/EntityReferenceSelection/BlockContentSelection.php b/core/modules/block_content/src/Plugin/EntityReferenceSelection/BlockContentSelection.php
new file mode 100644
index 0000000000..e53a2738fa
--- /dev/null
+++ b/core/modules/block_content/src/Plugin/EntityReferenceSelection/BlockContentSelection.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace Drupal\block_content\Plugin\EntityReferenceSelection;
+
+use Drupal\Core\Entity\Plugin\EntityReferenceSelection\DefaultSelection;
+
+/**
+ * Provides specific selection control for the block_content entity type.
+ *
+ * @EntityReferenceSelection(
+ *   id = "default:block_content",
+ *   label = @Translation("Custom block selection"),
+ *   entity_types = {"block_content"},
+ *   group = "default",
+ *   weight = 1
+ * )
+ */
+class BlockContentSelection extends DefaultSelection {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function buildEntityQuery($match = NULL, $match_operator = 'CONTAINS') {
+    $query = parent::buildEntityQuery($match, $match_operator);
+    // Only reusable blocks should be able to be referenced.
+    $query->condition('reusable', TRUE);
+    return $query;
+  }
+
+}
diff --git a/core/modules/block_content/tests/src/Kernel/BlockContentEntityReferenceSelectionTest.php b/core/modules/block_content/tests/src/Kernel/BlockContentEntityReferenceSelectionTest.php
deleted file mode 100644
index e593336fa3..0000000000
--- a/core/modules/block_content/tests/src/Kernel/BlockContentEntityReferenceSelectionTest.php
+++ /dev/null
@@ -1,189 +0,0 @@
-<?php
-
-namespace Drupal\Tests\block_content\Kernel;
-
-use Drupal\block_content\Entity\BlockContent;
-use Drupal\block_content\Entity\BlockContentType;
-use Drupal\block_content_test\Plugin\EntityReferenceSelection\TestSelection;
-use Drupal\KernelTests\KernelTestBase;
-
-/**
- * Tests EntityReference selection handlers don't return non-reusable blocks.
- *
- * @see block_content_query_entity_reference_alter()
- *
- * @group block_content
- */
-class BlockContentEntityReferenceSelectionTest extends KernelTestBase {
-
-  /**
-   * {@inheritdoc}
-   */
-  public static $modules = [
-    'block',
-    'block_content',
-    'block_content_test',
-    'system',
-    'user',
-  ];
-
-  /**
-   * The entity type manager.
-   *
-   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
-   */
-  protected $entityTypeManager;
-
-  /**
-   * Test reusable block.
-   *
-   * @var \Drupal\block_content\BlockContentInterface
-   */
-  protected $blockReusable;
-
-  /**
-   * Test non-reusable block.
-   *
-   * @var \Drupal\block_content\BlockContentInterface
-   */
-  protected $blockNonReusable;
-
-  /**
-   * Test selection handler.
-   *
-   * @var \Drupal\block_content_test\Plugin\EntityReferenceSelection\TestSelection
-   */
-  protected $selectionHandler;
-
-  /**
-   * Test block expectations.
-   *
-   * @var array
-   */
-  protected $expectations;
-
-  /**
-   * {@inheritdoc}
-   */
-  public function setUp() {
-    parent::setUp();
-    $this->installSchema('system', ['sequence']);
-    $this->installSchema('system', ['sequences']);
-    $this->installEntitySchema('user');
-    $this->installEntitySchema('block_content');
-
-    // Create a block content type.
-    $block_content_type = BlockContentType::create([
-      'id' => 'spiffy',
-      'label' => 'Mucho spiffy',
-      'description' => "Provides a block type that increases your site's spiffiness by up to 11%",
-    ]);
-    $block_content_type->save();
-    $this->entityTypeManager = $this->container->get('entity_type.manager');
-
-    // And reusable block content entities.
-    $this->blockReusable = BlockContent::create([
-      'info' => 'Reusable Block',
-      'type' => 'spiffy',
-    ]);
-    $this->blockReusable->save();
-    $this->blockNonReusable = BlockContent::create([
-      'info' => 'Non-reusable Block',
-      'type' => 'spiffy',
-      'reusable' => FALSE,
-    ]);
-    $this->blockNonReusable->save();
-
-    $configuration = [
-      'target_type' => 'block_content',
-      'target_bundles' => ['spiffy' => 'spiffy'],
-      'sort' => ['field' => '_none'],
-    ];
-    $this->selectionHandler = new TestSelection($configuration, '', '', $this->container->get('entity.manager'), $this->container->get('module_handler'), \Drupal::currentUser());
-
-    // Setup the 3 expectation cases.
-    $this->expectations = [
-      'both_blocks' => [
-        'spiffy' => [
-          $this->blockReusable->id() => $this->blockReusable->label(),
-          $this->blockNonReusable->id() => $this->blockNonReusable->label(),
-        ],
-      ],
-      'block_reusable' => ['spiffy' => [$this->blockReusable->id() => $this->blockReusable->label()]],
-      'block_non_reusable' => ['spiffy' => [$this->blockNonReusable->id() => $this->blockNonReusable->label()]],
-    ];
-  }
-
-  /**
-   * Tests to make sure queries without the expected tags are not altered.
-   *
-   * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
-   * @throws \Drupal\Component\Plugin\Exception\PluginNotFoundException
-   */
-  public function testQueriesNotAltered() {
-    // Ensure that queries without all the tags are not altered.
-    $query = $this->entityTypeManager->getStorage('block_content')->getQuery();
-    $this->assertCount(2, $query->execute());
-
-    $query = $this->entityTypeManager->getStorage('block_content')->getQuery();
-    $query->addTag('block_content_access');
-    $this->assertCount(2, $query->execute());
-
-    $query = $this->entityTypeManager->getStorage('block_content')->getQuery();
-    $query->addTag('entity_query_block_content');
-    $this->assertCount(2, $query->execute());
-  }
-
-  /**
-   * Test with no conditions set.
-   *
-   * @throws \Drupal\Core\Entity\EntityStorageException
-   */
-  public function testNoConditions() {
-    $this->assertEquals(
-      $this->expectations['block_reusable'],
-      $this->selectionHandler->getReferenceableEntities()
-    );
-
-    $this->blockNonReusable->setReusable();
-    $this->blockNonReusable->save();
-
-    // Ensure that the block is now returned as a referenceable entity.
-    $this->assertEquals(
-      $this->expectations['both_blocks'],
-      $this->selectionHandler->getReferenceableEntities()
-    );
-  }
-
-  /**
-   * Tests setting 'reusable' condition on different levels.
-   *
-   * @dataProvider fieldConditionProvider
-   *
-   * @throws \Exception
-   */
-  public function testFieldConditions($condition_type, $is_reusable) {
-    $this->selectionHandler->setTestMode($condition_type, $is_reusable);
-    $this->assertEquals(
-      $is_reusable ? $this->expectations['block_reusable'] : $this->expectations['block_non_reusable'],
-      $this->selectionHandler->getReferenceableEntities()
-    );
-  }
-
-  /**
-   * Provides possible fields and condition types.
-   */
-  public function fieldConditionProvider() {
-    $cases = [];
-    foreach (['base', 'group', 'nested_group'] as $condition_type) {
-      foreach ([TRUE, FALSE] as $reusable) {
-        $cases["$condition_type:" . ($reusable ? 'reusable' : 'non-reusable')] = [
-          $condition_type,
-          $reusable,
-        ];
-      }
-    }
-    return $cases;
-  }
-
-}
diff --git a/core/modules/block_content/tests/src/Kernel/BlockContentQueryAlterTest.php b/core/modules/block_content/tests/src/Kernel/BlockContentQueryAlterTest.php
new file mode 100644
index 0000000000..638ea99ce5
--- /dev/null
+++ b/core/modules/block_content/tests/src/Kernel/BlockContentQueryAlterTest.php
@@ -0,0 +1,87 @@
+<?php
+
+namespace Drupal\Tests\block_content\Kernel;
+
+use Drupal\block_content\Entity\BlockContent;
+use Drupal\block_content\Entity\BlockContentType;
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * Tests that block content queries are not altered.
+ *
+ * @see block_content_query_entity_reference_alter()
+ *
+ * @group block_content
+ */
+class BlockContentQueryAlterTest extends KernelTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = [
+    'block',
+    'block_content',
+    'system',
+    'user',
+  ];
+
+  /**
+   * The block content storage.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface
+   */
+  protected $blockContentStorage;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setUp() {
+    parent::setUp();
+    $this->installSchema('system', ['sequence']);
+    $this->installSchema('system', ['sequences']);
+    $this->installEntitySchema('user');
+    $this->installEntitySchema('block_content');
+
+    // Create a block content type.
+    $block_content_type = BlockContentType::create([
+      'id' => 'spiffy',
+      'label' => 'Mucho spiffy',
+      'description' => "Provides a block type that increases your site's spiffiness by up to 11%",
+    ]);
+    $block_content_type->save();
+    $this->blockContentStorage = $this->container->get('entity_type.manager')->getStorage('block_content');
+
+    // And reusable block content entities.
+    $block_reusable = BlockContent::create([
+      'info' => 'Reusable Block',
+      'type' => 'spiffy',
+    ]);
+    $block_reusable->save();
+    $block__non_reusable = BlockContent::create([
+      'info' => 'Non-reusable Block',
+      'type' => 'spiffy',
+      'reusable' => FALSE,
+    ]);
+    $block__non_reusable->save();
+  }
+
+  /**
+   * Tests to make sure queries without the expected tags are not altered.
+   *
+   * @see block_content_query_entity_reference_alter()
+   */
+  public function testQueriesNotAltered() {
+    // Ensure that queries without all the tags are not altered.
+    $query = $this->blockContentStorage->getQuery();
+    $this->assertCount(2, $query->execute());
+
+    $query = $this->blockContentStorage->getQuery();
+    $query->addTag('block_content_access');
+    $this->assertCount(2, $query->execute());
+
+    $query = $this->blockContentStorage->getQuery();
+    $query->addTag('entity_query_block_content');
+    $this->assertCount(2, $query->execute());
+  }
+
+}
diff --git a/core/modules/system/tests/src/Functional/Entity/EntityReferenceSelection/EntityReferenceSelectionAccessTest.php b/core/modules/system/tests/src/Functional/Entity/EntityReferenceSelection/EntityReferenceSelectionAccessTest.php
index 3772f3a97b..f7e58bdacc 100644
--- a/core/modules/system/tests/src/Functional/Entity/EntityReferenceSelection/EntityReferenceSelectionAccessTest.php
+++ b/core/modules/system/tests/src/Functional/Entity/EntityReferenceSelection/EntityReferenceSelectionAccessTest.php
@@ -2,6 +2,10 @@
 
 namespace Drupal\Tests\system\Functional\Entity\EntityReferenceSelection;
 
+use Drupal\block_content\Entity\BlockContent;
+use Drupal\block_content\Entity\BlockContentType;
+use Drupal\block_content\Plugin\EntityReferenceSelection\BlockContentSelection;
+use Drupal\block_content_test\Plugin\EntityReferenceSelection\TestSelection;
 use Drupal\comment\Tests\CommentTestTrait;
 use Drupal\Component\Utility\Html;
 use Drupal\Core\Language\LanguageInterface;
@@ -26,7 +30,7 @@ class EntityReferenceSelectionAccessTest extends BrowserTestBase {
    *
    * @var array
    */
-  public static $modules = ['node', 'comment'];
+  public static $modules = ['node', 'comment', 'block_content', 'block_content_test'];
 
   protected function setUp() {
     parent::setUp();
@@ -507,4 +511,100 @@ public function testCommentHandler() {
     $this->assertReferenceable($selection_options, $referenceable_tests, 'Comment handler (comment + node admin)');
   }
 
+  /**
+   * Test the comment-specific overrides of the entity handler.
+   *
+   * @dataProvider blockContentProvider
+   *
+   * @throws \Exception
+   */
+  public function testBlockContentHandlers($custom_selection_plugin, $condition_type, $is_reusable, $expectation) {
+    // Create a block content type.
+    $block_content_type = BlockContentType::create([
+      'id' => 'spiffy',
+      'label' => 'Mucho spiffy',
+      'description' => "Provides a block type that increases your site's spiffiness by up to 11%",
+    ]);
+    $block_content_type->save();
+
+    // And reusable block content entities.
+    $block_reusable = BlockContent::create([
+      'info' => 'Reusable Block',
+      'type' => 'spiffy',
+    ]);
+    $block_reusable->save();
+    $block_non_reusable = BlockContent::create([
+      'info' => 'Non-reusable Block',
+      'type' => 'spiffy',
+      'reusable' => FALSE,
+    ]);
+    $block_non_reusable->save();
+
+
+    // Setup the 3 expectation cases.
+    $expectations = [
+      'both_blocks' => [
+        'spiffy' => [
+          $block_reusable->id() => $block_reusable->label(),
+          $block_non_reusable->id() => $block_non_reusable->label(),
+        ],
+      ],
+      'block_reusable' => ['spiffy' => [$block_reusable->id() => $block_reusable->label()]],
+      'block_non_reusable' => ['spiffy' => [$block_non_reusable->id() => $block_non_reusable->label()]],
+    ];
+    $configuration = [
+      'target_type' => 'block_content',
+      'target_bundles' => ['spiffy' => 'spiffy'],
+      'sort' => ['field' => '_none'],
+    ];
+
+    if ($custom_selection_plugin) {
+      // For selection plugins besides BlockContentSelection the queries will be
+      // altered to not include non-reusable blocks unless a condition on the
+      // 'reusable' field is explicitly set.
+      // @see block_content_query_entity_reference_alter()
+      $selectionHandler = new TestSelection($configuration, '', '', $this->container->get('entity.manager'), $this->container->get('module_handler'), \Drupal::currentUser());
+      // Set the test mode so that the conditions will be set at different
+      // nested levels and with different values.
+      $selectionHandler->setTestMode($condition_type, $is_reusable);
+    }
+    else {
+      $selectionHandler = new BlockContentSelection($configuration, '', '', $this->container->get('entity.manager'), $this->container->get('module_handler'), \Drupal::currentUser());
+    }
+
+    $this->assertEquals(
+      $expectations[$expectation],
+      $selectionHandler->getReferenceableEntities()
+    );
+  }
+
+  /**
+   * Dataprovider for blockContentProvider().
+   */
+  public function blockContentProvider() {
+    $cases['block_content_selection_plugin'] = [
+      FALSE,
+      NULL,
+      NULL,
+      'block_reusable',
+    ];
+    $cases['custom_selection_plugin:no_condition'] = [
+      TRUE,
+      NULL,
+      NULL,
+      'block_reusable',
+    ];
+    foreach (['base', 'group', 'nested_group'] as $condition_type) {
+      foreach ([TRUE, FALSE] as $reusable) {
+        $cases["custom_selection_plugin:$condition_type:" . ($reusable ? 'reusable' : 'non-reusable')] = [
+          TRUE,
+          $condition_type,
+          $reusable,
+          $reusable ? 'block_reusable' : 'block_non_reusable',
+        ];
+      }
+    }
+    return $cases;
+  }
+
 }