diff --git a/src/main/java/org/jboss/netty/channel/DefaultChannelFuture.java b/src/main/java/org/jboss/netty/channel/DefaultChannelFuture.java
index 4c347cee12..7c36f07519 100644
--- a/src/main/java/org/jboss/netty/channel/DefaultChannelFuture.java
+++ b/src/main/java/org/jboss/netty/channel/DefaultChannelFuture.java
@@ -364,6 +364,10 @@ public class DefaultChannelFuture implements ChannelFuture {
     }
 
     public boolean setFailure(Throwable cause) {
+        if (cause == null) {
+            throw new NullPointerException("cause");
+        }
+
         synchronized (this) {
             // Allow only once.
             if (done) {