diff --git a/java_gen/templates/of_class.java b/java_gen/templates/of_class.java
index 18dae2b..eae75ba 100644
--- a/java_gen/templates/of_class.java
+++ b/java_gen/templates/of_class.java
@@ -155,7 +155,7 @@
     final static Writer WRITER = new Writer();
     static class Writer implements OFMessageWriter<${impl_class}> {
         @Override
-        public int write(ChannelBuffer bb, ${impl_class} message) {
+        public void write(ChannelBuffer bb, ${impl_class} message) {
 //:: if not msg.is_fixed_length:
             int startIndex = bb.writerIndex();
 //:: #end