diff --git a/netty/src/main/java/io/grpc/netty/NettyServerHandler.java b/netty/src/main/java/io/grpc/netty/NettyServerHandler.java
index d5432148cb..96485b43df 100644
--- a/netty/src/main/java/io/grpc/netty/NettyServerHandler.java
+++ b/netty/src/main/java/io/grpc/netty/NettyServerHandler.java
@@ -774,7 +774,8 @@ class NettyServerHandler extends AbstractNettyHandler {
     @Override
     public void ping() {
       ChannelFuture pingFuture = encoder().writePing(
-          ctx, false /* isAck */, KEEPALIVE_PING_BUF, ctx.newPromise());
+          // slice KEEPALIVE_PING_BUF because tls handler may modify the reader index
+          ctx, false /* isAck */, KEEPALIVE_PING_BUF.slice(), ctx.newPromise());
       ctx.flush();
       if (transportTracer != null) {
         pingFuture.addListener(new ChannelFutureListener() {