diff --git a/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/CacheKeyGenerator.java b/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/CacheKeyGenerator.java
index 8a20212d6..f09805b1b 100644
--- a/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/CacheKeyGenerator.java
+++ b/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/CacheKeyGenerator.java
@@ -154,7 +154,7 @@ class CacheKeyGenerator {
         }
         Collections.sort(variantHeaderNames);
 
-        StringBuilder buf;
+        final StringBuilder buf;
         try {
             buf = new StringBuilder("{");
             boolean first = true;
diff --git a/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/CachingExec.java b/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/CachingExec.java
index b39e39aaa..38a17cb22 100644
--- a/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/CachingExec.java
+++ b/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/CachingExec.java
@@ -526,7 +526,7 @@ public class CachingExec implements ClientExecChain {
         final VersionInfo vi = VersionInfo.loadVersionInfo("org.apache.hc.client5", getClass().getClassLoader());
         final String release = (vi != null) ? vi.getRelease() : VersionInfo.UNAVAILABLE;
 
-        String value;
+        final String value;
         final int major = pv.getMajor();
         final int minor = pv.getMinor();
         if ("http".equalsIgnoreCase(pv.getProtocol())) {
diff --git a/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/HeapResourceFactory.java b/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/HeapResourceFactory.java
index 67a0f1ed3..946db58dc 100644
--- a/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/HeapResourceFactory.java
+++ b/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/HeapResourceFactory.java
@@ -67,7 +67,7 @@ public class HeapResourceFactory implements ResourceFactory {
     public Resource copy(
             final String requestId,
             final Resource resource) throws IOException {
-        byte[] body;
+        final byte[] body;
         if (resource instanceof HeapResource) {
             body = ((HeapResource) resource).getByteArray();
         } else {
diff --git a/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/memcached/MemcachedCacheEntryImpl.java b/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/memcached/MemcachedCacheEntryImpl.java
index 17a2babb6..c16e3652b 100644
--- a/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/memcached/MemcachedCacheEntryImpl.java
+++ b/httpclient5-cache/src/main/java/org/apache/hc/client5/http/impl/cache/memcached/MemcachedCacheEntryImpl.java
@@ -58,7 +58,7 @@ public class MemcachedCacheEntryImpl implements MemcachedCacheEntry {
     @Override
     synchronized public byte[] toByteArray() {
         final ByteArrayOutputStream bos = new ByteArrayOutputStream();
-        ObjectOutputStream oos;
+        final ObjectOutputStream oos;
         try {
             oos = new ObjectOutputStream(bos);
             oos.writeObject(this.key);
@@ -92,9 +92,9 @@ public class MemcachedCacheEntryImpl implements MemcachedCacheEntry {
     @Override
     synchronized public void set(final byte[] bytes) {
         final ByteArrayInputStream bis = new ByteArrayInputStream(bytes);
-        ObjectInputStream ois;
-        String s;
-        HttpCacheEntry entry;
+        final ObjectInputStream ois;
+        final String s;
+        final HttpCacheEntry entry;
         try {
             ois = new ObjectInputStream(bis);
             s = (String)ois.readObject();