diff --git a/lib/fluent/plugin/filter_kubernetes_metadata.rb b/lib/fluent/plugin/filter_kubernetes_metadata.rb
index 0ebc7a5..1f76d26 100644
--- a/lib/fluent/plugin/filter_kubernetes_metadata.rb
+++ b/lib/fluent/plugin/filter_kubernetes_metadata.rb
@@ -204,13 +204,13 @@ def configure(conf)
       end
 
       # Caches pod/namespace UID tuples for a given container UID.
-      @id_cache = LruRedux::TTL::ThreadSafeCache.new(@cache_size, @cache_ttl)
+      @id_cache = LruRedux::TTL::Cache.new(@cache_size, @cache_ttl)
 
       # Use the container UID as the key to fetch a hash containing pod metadata
-      @cache = LruRedux::TTL::ThreadSafeCache.new(@cache_size, @cache_ttl)
+      @cache = LruRedux::TTL::Cache.new(@cache_size, @cache_ttl)
 
       # Use the namespace UID as the key to fetch a hash containing namespace metadata
-      @namespace_cache = LruRedux::TTL::ThreadSafeCache.new(@cache_size, @cache_ttl)
+      @namespace_cache = LruRedux::TTL::Cache.new(@cache_size, @cache_ttl)
 
       @tag_to_kubernetes_name_regexp_compiled = Regexp.compile(@tag_to_kubernetes_name_regexp)