diff --git a/patternkit.services.yml b/patternkit.services.yml
index 44e9e04..3b56a04 100644
--- a/patternkit.services.yml
+++ b/patternkit.services.yml
@@ -11,7 +11,7 @@ services:
     arguments: ['@patternkit.library.discovery.collector']
   patternkit.library.discovery.collector:
     class: Drupal\patternkit\PatternLibraryCollector
-    arguments: ['@cache.discovery', '@config.factory', '@file_system', '@plugin.manager.library.pattern', '@lock', '@module_handler', '@app.root', '@theme.manager']
+    arguments: ['@cache.discovery', '@config.factory', '@file_system', '@plugin.manager.library.pattern', '@lock', '@logger.channel.default', '@module_handler', '@app.root', '@theme.manager']
     tags:
       - { name: needs_destruction }
   patternkit.library.discovery.parser.file:
diff --git a/src/PatternLibraryCollector.php b/src/PatternLibraryCollector.php
index 2d7177f..c053a13 100644
--- a/src/PatternLibraryCollector.php
+++ b/src/PatternLibraryCollector.php
@@ -13,6 +13,7 @@
 use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\File\FileSystemInterface;
+use Drupal\Core\Logger\LoggerChannelInterface;
 use Drupal\Core\Serialization\Yaml;
 use Drupal\Core\Theme\ThemeManagerInterface;
 use Drupal\patternkit\Form\PatternkitSettingsForm;
@@ -50,6 +51,9 @@ class PatternLibraryCollector extends CacheCollector implements ContainerInjecti
   /** @var \Drupal\patternkit\PatternLibraryPluginManager */
   protected $libraryPluginManager;
 
+  /** @var \Drupal\Core\Logger\LoggerChannelInterface */
+  protected $logger;
+
   /** @var \Drupal\Core\Extension\ModuleHandlerInterface */
   protected $moduleHandler;
 
@@ -74,6 +78,8 @@ class PatternLibraryCollector extends CacheCollector implements ContainerInjecti
    *   Provide the file system service.
    * @param \Drupal\Core\Lock\LockBackendInterface $lock
    *   Provide the lock backend.
+   * @param \Drupal\Core\Logger\LoggerChannelInterface $logger
+   *   Provide the logging channel.
    * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
    *   Provide a module handler.
    * @param \Drupal\patternkit\PatternLibraryPluginManager $library_plugin_manager
@@ -89,6 +95,7 @@ public function __construct(
     FileSystemInterface $file_system,
     PatternLibraryPluginManager $library_plugin_manager,
     LockBackendInterface $lock,
+    LoggerChannelInterface $logger,
     ModuleHandlerInterface $module_handler,
     $root,
     ThemeManagerInterface $theme_manager) {
@@ -97,6 +104,7 @@ public function __construct(
     $this->config = $this->configFactory->get(PatternkitSettingsForm::SETTINGS);
     $this->fileSystem = $file_system;
     $this->libraryPluginManager = $library_plugin_manager;
+    $this->logger = $logger;
     $this->moduleHandler = $module_handler;
     $this->root = $root;
     $this->themeManager = $theme_manager;
@@ -120,6 +128,8 @@ public static function create(ContainerInterface $container): self {
     $file_system = $container->get('file_system');
     /** @var \Drupal\Core\Lock\LockBackendInterface $lock */
     $lock = $container->get('lock');
+    /** @var \Drupal\Core\Logger\LoggerChannelInterface $logger */
+    $logger = $container->get('@logger.channel.default');
     /** @var \Drupal\Core\Extension\ModuleHandlerInterface $module_handler */
     $module_handler = $container->get('module_handler');
     /** @var string $root */
@@ -132,6 +142,7 @@ public static function create(ContainerInterface $container): self {
       $file_system,
       $library_plugin_manager,
       $lock,
+      $logger,
       $module_handler,
       $root,
       $theme_manager);
@@ -159,8 +170,13 @@ public function getLibraryDefinitions(): array {
       // (if cache enabled, otherwise just a slow, redundant memcache set).
       if ($cache_enabled) {
         // Explicit copy of the data into cache_set to avoid implicit copy.
+        // @todo Evaluate encoding via JSON instead to shrink data size.
         $this->cache->set(static::PERSISTENT_CACHE_ID,
           $cached_metadata);
+        $cache = $this->cache->get(static::PERSISTENT_CACHE_ID);
+        if ($cache->data !== $cached_metadata) {
+          $this->logger->warning('Error storing Patternkit Library Metadata in cache. Check that memcache or your caching module has be configured correctly.');
+        }
       }
     }
     return $cached_metadata;