diff -u b/core/modules/block/src/Tests/BlockTest.php b/core/modules/block/src/Tests/BlockTest.php
--- b/core/modules/block/src/Tests/BlockTest.php
+++ b/core/modules/block/src/Tests/BlockTest.php
@@ -485,11 +485,8 @@
    * Tests block_node_type_delete.
    */
   public function testBlockNodeTypeDelete() {
-    $node_type1 = NodeType::create(['id' => 'test_nodetype1', 'name' => $this->randomString()]);
-    $node_type1->save();
-
-    $node_type2 = NodeType::create(['id' => 'test_nodetype2', 'name' => $this->randomString()]);
-    $node_type2->save();
+    $node_type1 = $this->drupalCreateContentType();
+    $node_type2 = $this->drupalCreateContentType();
 
     $block = Block::create([
       'id' => $this->randomMachineName(),