diff --git a/core/lib/Drupal/Component/Plugin/Discovery/DerivativeDiscoveryDecorator.php b/core/lib/Drupal/Component/Plugin/Discovery/DerivativeDiscoveryDecorator.php
index e245874..08aae21 100644
--- a/core/lib/Drupal/Component/Plugin/Discovery/DerivativeDiscoveryDecorator.php
+++ b/core/lib/Drupal/Component/Plugin/Discovery/DerivativeDiscoveryDecorator.php
@@ -65,6 +65,10 @@ public function getDefinitions() {
   protected function getDerivatives(array $base_plugin_definitions) {
     $plugin_definitions = array();
     foreach ($base_plugin_definitions as $base_plugin_id => $plugin_definition) {
+      // @todo Remove this check once http://drupal.org/node/1780396 is resolved.
+      if (!module_exists($plugin_definition['module'])) {
+        continue;
+      }
       $derivative_fetcher = $this->getDerivativeFetcher($base_plugin_id, $plugin_definition);
       if ($derivative_fetcher) {
         $derivative_definitions = $derivative_fetcher->getDerivativeDefinitions($plugin_definition);
diff --git a/core/modules/block/block.module b/core/modules/block/block.module
index 8afc6de..eda00a6 100644
--- a/core/modules/block/block.module
+++ b/core/modules/block/block.module
@@ -470,16 +470,16 @@ function block_manager() {
 /**
  * Loads a block object from the database.
  *
- * @param $plugin_id
+ * @param string $plugin_id
  *   The plugin id to load.
- * @param $conf
+ * @param array $conf
  *   An optional configuration array for creating a block instance from php
  *   instead of relying on configuration xml.
  *
  * @return
  *   A block object.
  */
-function block_load($plugin_id, $conf = array()) {
+function block_load($plugin_id, array $conf = array()) {
   try {
     $block = block_manager()->getInstance(array('config' => $plugin_id));
   }
diff --git a/core/modules/block/lib/Drupal/block/Plugin/system/plugin_ui/BlockPluginUI.php b/core/modules/block/lib/Drupal/block/Plugin/system/plugin_ui/BlockPluginUI.php
index 541ff87..bc41a78 100644
--- a/core/modules/block/lib/Drupal/block/Plugin/system/plugin_ui/BlockPluginUI.php
+++ b/core/modules/block/lib/Drupal/block/Plugin/system/plugin_ui/BlockPluginUI.php
@@ -12,6 +12,7 @@
  *   title = @Translation("Block Library"),
  *   title_attribute = "subject",
  *   menu = TRUE,
+ *   module = "block",
  *   all_plugins = @Translation("All Blocks"),
  *   link_title = @Translation("Configure Block"),
  *   config_path = "admin/structure/block/manage",
diff --git a/core/modules/statistics/lib/Drupal/statistics/Tests/StatisticsReportsTest.php b/core/modules/statistics/lib/Drupal/statistics/Tests/StatisticsReportsTest.php
index 80e6c38..f45d4cd 100644
--- a/core/modules/statistics/lib/Drupal/statistics/Tests/StatisticsReportsTest.php
+++ b/core/modules/statistics/lib/Drupal/statistics/Tests/StatisticsReportsTest.php
@@ -82,7 +82,7 @@ function testPopularContentBlock() {
     drupal_http_request($stats_path, array('method' => 'POST', 'data' => $post, 'headers' => $headers, 'timeout' => 10000));
 
     // Configure and save the block.
-    $block = block_load('statistics', 'popular');
+    $block = block_load('statistics_popular_block');
     $block->theme = variable_get('theme_default', 'stark');
     $block->status = 1;
     $block->pages = '';