diff --git a/httpclient-cache/src/main/java/org/apache/http/impl/client/cache/memcached/MemcachedHttpCacheStorage.java b/httpclient-cache/src/main/java/org/apache/http/impl/client/cache/memcached/MemcachedHttpCacheStorage.java
index caa8c51aa..d6cd1a430 100644
--- a/httpclient-cache/src/main/java/org/apache/http/impl/client/cache/memcached/MemcachedHttpCacheStorage.java
+++ b/httpclient-cache/src/main/java/org/apache/http/impl/client/cache/memcached/MemcachedHttpCacheStorage.java
@@ -47,8 +47,8 @@ import org.apache.http.impl.client.cache.DefaultHttpCacheEntrySerializer;
 
 public class MemcachedHttpCacheStorage implements HttpCacheStorage {
 
-    private MemcachedClientIF client;
-    private HttpCacheEntrySerializer serializer;
+    private final MemcachedClientIF client;
+    private final HttpCacheEntrySerializer serializer;
     private final int maxUpdateRetries;
 
     public MemcachedHttpCacheStorage(InetSocketAddress address) throws IOException {