diff --git a/jetty-io/src/main/java/org/eclipse/jetty/io/NetworkTrafficSelectChannelEndPoint.java b/jetty-io/src/main/java/org/eclipse/jetty/io/NetworkTrafficSelectChannelEndPoint.java
index 5193f073745..65878ce5d2c 100644
--- a/jetty-io/src/main/java/org/eclipse/jetty/io/NetworkTrafficSelectChannelEndPoint.java
+++ b/jetty-io/src/main/java/org/eclipse/jetty/io/NetworkTrafficSelectChannelEndPoint.java
@@ -57,7 +57,7 @@ public class NetworkTrafficSelectChannelEndPoint extends SelectChannelEndPoint
             if (b.hasRemaining())
             {
                 int position = b.position();
-                flushed|=super.flush(b);
+                flushed&=super.flush(b);
                 int l=b.position()-position;
                 notifyOutgoing(b, position, l);
                 if (!flushed)