diff --git a/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php b/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php
index 1c78697..1bc4535 100644
--- a/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php
+++ b/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php
@@ -26,7 +26,7 @@
  *   form_controller_class = {
  *     "default" = "Drupal\block\BlockFormController"
  *   },
- *   config_prefix = "plugin.core.block",
+ *   config_prefix = "block.block",
  *   fieldable = FALSE,
  *   entity_keys = {
  *     "id" = "id",
diff --git a/core/modules/block/lib/Drupal/block/Tests/BlockStorageUnitTest.php b/core/modules/block/lib/Drupal/block/Tests/BlockStorageUnitTest.php
index 6695681..4e5b8bf 100644
--- a/core/modules/block/lib/Drupal/block/Tests/BlockStorageUnitTest.php
+++ b/core/modules/block/lib/Drupal/block/Tests/BlockStorageUnitTest.php
@@ -86,7 +86,7 @@ protected function createTests() {
     $this->assertTrue($entity instanceof Block, 'The newly created entity is a Block.');
 
     // Verify all of the block properties.
-    $actual_properties = config('plugin.core.block.stark.test_block')->get();
+    $actual_properties = config('block.block.stark.test_block')->get();
     $this->assertTrue(!empty($actual_properties['uuid']), 'The block UUID is set.');
     unset($actual_properties['uuid']);
 
@@ -177,14 +177,14 @@ protected function deleteTests() {
 
     // Ensure that the storage isn't currently empty.
     $config_storage = $this->container->get('config.storage');
-    $config = $config_storage->listAll('plugin.core.block.');
+    $config = $config_storage->listAll('block.block.');
     $this->assertFalse(empty($config), 'There are blocks in config storage.');
 
     // Delete the block.
     $entity->delete();
 
     // Ensure that the storage is now empty.
-    $config = $config_storage->listAll('plugin.core.block.');
+    $config = $config_storage->listAll('block.block.');
     $this->assertTrue(empty($config), 'There are no blocks in config storage.');
   }
 
diff --git a/core/modules/block/lib/Drupal/block/Tests/NewDefaultThemeBlocksTest.php b/core/modules/block/lib/Drupal/block/Tests/NewDefaultThemeBlocksTest.php
index d9be6f4..190570c 100644
--- a/core/modules/block/lib/Drupal/block/Tests/NewDefaultThemeBlocksTest.php
+++ b/core/modules/block/lib/Drupal/block/Tests/NewDefaultThemeBlocksTest.php
@@ -56,8 +56,8 @@ function testNewDefaultThemeBlocks() {
     // Ensure that the new theme has all the blocks as the previous default.
     // @todo Replace the string manipulation below once the configuration
     //   system provides a method for extracting an ID in a given namespace.
-    $default_prefix = "plugin.core.block.$default_theme";
-    $new_prefix = "plugin.core.block.$new_theme";
+    $default_prefix = "block.block.$default_theme";
+    $new_prefix = "block.block.$new_theme";
     $default_block_names = config_get_storage_names_with_prefix($default_prefix);
     $new_blocks = array_flip(config_get_storage_names_with_prefix($new_prefix));
     $this->assertTrue(count($default_block_names) == count($new_blocks), 'The new default theme has the same number of blocks as the previous theme.');
@@ -65,8 +65,8 @@ function testNewDefaultThemeBlocks() {
       // Make sure the configuration object name is in the expected format.
       if (strpos($default_block_name, $default_prefix) === 0) {
         // Remove the matching block from the list of blocks in the new theme.
-        // E.g., if the old theme has plugin.core.block.stark.admin,
-        // unset plugin.core.block.bartik.admin.
+        // E.g., if the old theme has block.block.stark.admin,
+        // unset block.block.bartik.admin.
         $id = substr($default_block_name, (strlen($default_prefix) + 1));
         unset($new_blocks[$new_prefix . '.' . $id]);
       }
diff --git a/core/modules/block/tests/config/plugin.core.block.stark.test_block.yml b/core/modules/block/tests/config/block.block.stark.test_block.yml
similarity index 100%
rename from core/modules/block/tests/config/plugin.core.block.stark.test_block.yml
rename to core/modules/block/tests/config/block.block.stark.test_block.yml
diff --git a/core/profiles/standard/config/plugin.core.block.bartik.content.yml b/core/profiles/standard/config/block.block.bartik.content.yml
similarity index 100%
rename from core/profiles/standard/config/plugin.core.block.bartik.content.yml
rename to core/profiles/standard/config/block.block.bartik.content.yml
diff --git a/core/profiles/standard/config/plugin.core.block.bartik.footer.yml b/core/profiles/standard/config/block.block.bartik.footer.yml
similarity index 100%
rename from core/profiles/standard/config/plugin.core.block.bartik.footer.yml
rename to core/profiles/standard/config/block.block.bartik.footer.yml
diff --git a/core/profiles/standard/config/plugin.core.block.bartik.help.yml b/core/profiles/standard/config/block.block.bartik.help.yml
similarity index 100%
rename from core/profiles/standard/config/plugin.core.block.bartik.help.yml
rename to core/profiles/standard/config/block.block.bartik.help.yml
diff --git a/core/profiles/standard/config/plugin.core.block.bartik.login.yml b/core/profiles/standard/config/block.block.bartik.login.yml
similarity index 100%
rename from core/profiles/standard/config/plugin.core.block.bartik.login.yml
rename to core/profiles/standard/config/block.block.bartik.login.yml
diff --git a/core/profiles/standard/config/plugin.core.block.bartik.powered.yml b/core/profiles/standard/config/block.block.bartik.powered.yml
similarity index 100%
rename from core/profiles/standard/config/plugin.core.block.bartik.powered.yml
rename to core/profiles/standard/config/block.block.bartik.powered.yml
diff --git a/core/profiles/standard/config/plugin.core.block.bartik.search.yml b/core/profiles/standard/config/block.block.bartik.search.yml
similarity index 100%
rename from core/profiles/standard/config/plugin.core.block.bartik.search.yml
rename to core/profiles/standard/config/block.block.bartik.search.yml
diff --git a/core/profiles/standard/config/plugin.core.block.bartik.tools.yml b/core/profiles/standard/config/block.block.bartik.tools.yml
similarity index 100%
rename from core/profiles/standard/config/plugin.core.block.bartik.tools.yml
rename to core/profiles/standard/config/block.block.bartik.tools.yml
diff --git a/core/profiles/standard/config/plugin.core.block.seven.content.yml b/core/profiles/standard/config/block.block.seven.content.yml
similarity index 100%
rename from core/profiles/standard/config/plugin.core.block.seven.content.yml
rename to core/profiles/standard/config/block.block.seven.content.yml
diff --git a/core/profiles/standard/config/plugin.core.block.seven.help.yml b/core/profiles/standard/config/block.block.seven.help.yml
similarity index 100%
rename from core/profiles/standard/config/plugin.core.block.seven.help.yml
rename to core/profiles/standard/config/block.block.seven.help.yml
diff --git a/core/profiles/standard/config/plugin.core.block.seven.login.yml b/core/profiles/standard/config/block.block.seven.login.yml
similarity index 100%
rename from core/profiles/standard/config/plugin.core.block.seven.login.yml
rename to core/profiles/standard/config/block.block.seven.login.yml