diff --git a/jetty-io/src/main/java/org/eclipse/jetty/io/WriteFlusher.java b/jetty-io/src/main/java/org/eclipse/jetty/io/WriteFlusher.java
index 9e51aa5dbbc..eec6ee6b506 100644
--- a/jetty-io/src/main/java/org/eclipse/jetty/io/WriteFlusher.java
+++ b/jetty-io/src/main/java/org/eclipse/jetty/io/WriteFlusher.java
@@ -230,7 +230,7 @@ abstract public class WriteFlusher
     {
         private final C _context;
         private final Callback<C> _callback;
-        private ByteBuffer[] _buffers;
+        private final ByteBuffer[] _buffers;
         
         private PendingState(ByteBuffer[] buffers, C context, Callback<C> callback)
         {