diff --git a/handler-proxy/src/main/java/io/netty/handler/proxy/HttpProxyHandler.java b/handler-proxy/src/main/java/io/netty/handler/proxy/HttpProxyHandler.java
index 39305bd29b..278eb10316 100644
--- a/handler-proxy/src/main/java/io/netty/handler/proxy/HttpProxyHandler.java
+++ b/handler-proxy/src/main/java/io/netty/handler/proxy/HttpProxyHandler.java
@@ -18,11 +18,9 @@ package io.netty.handler.proxy;
 
 import static java.util.Objects.requireNonNull;
 
-import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelPipeline;
-import io.netty.handler.codec.base64.Base64;
 import io.netty.handler.codec.http.DefaultFullHttpRequest;
 import io.netty.handler.codec.http.FullHttpRequest;
 import io.netty.handler.codec.http.HttpClientCodec;
@@ -35,16 +33,20 @@ import io.netty.handler.codec.http.HttpUtil;
 import io.netty.handler.codec.http.HttpVersion;
 import io.netty.handler.codec.http.LastHttpContent;
 import io.netty.util.AsciiString;
-import io.netty.util.CharsetUtil;
 
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+import java.util.Base64;
 
 public final class HttpProxyHandler extends ProxyHandler {
 
     private static final String PROTOCOL = "http";
     private static final String AUTH_BASIC = "basic";
 
+    private static final byte[] BASIC_BYTES = "Basic ".getBytes(StandardCharsets.UTF_8);
+
     private final HttpClientCodec codec = new HttpClientCodec();
     private final String username;
     private final String password;
@@ -93,13 +95,12 @@ public final class HttpProxyHandler extends ProxyHandler {
         this.username = username;
         this.password = password;
 
-        ByteBuf authz = Unpooled.copiedBuffer(username + ':' + password, CharsetUtil.UTF_8);
-        ByteBuf authzBase64 = Base64.encode(authz, false);
+        byte[] authzBase64 = Base64.getEncoder().encode(
+                (username + ':' + password).getBytes(StandardCharsets.UTF_8));
+        byte[] authzHeader = Arrays.copyOf(BASIC_BYTES, 6 + authzBase64.length);
+        System.arraycopy(authzBase64, 0, authzHeader, 6, authzBase64.length);
 
-        authorization = new AsciiString("Basic " + authzBase64.toString(CharsetUtil.US_ASCII));
-
-        authz.release();
-        authzBase64.release();
+        authorization = new AsciiString(authzHeader, /*copy=*/ false);
 
         this.outboundHeaders = headers;
         this.ignoreDefaultPortsInConnectHostHeader = ignoreDefaultPortsInConnectHostHeader;
diff --git a/handler-proxy/src/test/java/io/netty/handler/proxy/HttpProxyServer.java b/handler-proxy/src/test/java/io/netty/handler/proxy/HttpProxyServer.java
index eb216b574d..a2defa4146 100644
--- a/handler-proxy/src/test/java/io/netty/handler/proxy/HttpProxyServer.java
+++ b/handler-proxy/src/test/java/io/netty/handler/proxy/HttpProxyServer.java
@@ -16,13 +16,11 @@
 
 package io.netty.handler.proxy;
 
-import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.socket.SocketChannel;
 import io.netty.handler.codec.LineBasedFrameDecoder;
-import io.netty.handler.codec.base64.Base64;
 import io.netty.handler.codec.http.DefaultFullHttpResponse;
 import io.netty.handler.codec.http.FullHttpRequest;
 import io.netty.handler.codec.http.FullHttpResponse;
@@ -32,11 +30,12 @@ import io.netty.handler.codec.http.HttpObjectAggregator;
 import io.netty.handler.codec.http.HttpResponseStatus;
 import io.netty.handler.codec.http.HttpServerCodec;
 import io.netty.handler.codec.http.HttpVersion;
-import io.netty.util.CharsetUtil;
 import io.netty.util.internal.SocketUtils;
 
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
+import java.nio.charset.StandardCharsets;
+import java.util.Base64;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.Matchers.*;
@@ -88,15 +87,11 @@ final class HttpProxyServer extends ProxyServer {
             CharSequence authz = req.headers().get(HttpHeaderNames.PROXY_AUTHORIZATION);
             if (authz != null) {
                 String[] authzParts = authz.toString().split(" ", 2);
-                ByteBuf authzBuf64 = Unpooled.copiedBuffer(authzParts[1], CharsetUtil.US_ASCII);
-                ByteBuf authzBuf = Base64.decode(authzBuf64);
+                byte[] authzCreds = Base64.getDecoder().decode(authzParts[1]);
 
                 String expectedAuthz = username + ':' + password;
                 authzSuccess = "Basic".equals(authzParts[0]) &&
-                               expectedAuthz.equals(authzBuf.toString(CharsetUtil.US_ASCII));
-
-                authzBuf64.release();
-                authzBuf.release();
+                        expectedAuthz.equals(new String(authzCreds, StandardCharsets.UTF_8));
             }
         } else {
             authzSuccess = true;
@@ -159,7 +154,7 @@ final class HttpProxyServer extends ProxyServer {
             ctx.pipeline().get(HttpServerCodec.class).removeOutboundHandler();
 
             if (sendGreeting) {
-                ctx.write(Unpooled.copiedBuffer("0\n", CharsetUtil.US_ASCII));
+                ctx.write(Unpooled.copiedBuffer("0\n", StandardCharsets.US_ASCII));
             }
 
             return true;