diff --git a/src/main/java/net/openhft/chronicle/hash/replication/EngineReplicationLangBytesConsumer.java b/src/main/java/net/openhft/chronicle/hash/replication/EngineReplicationLangBytesConsumer.java
index cd33b95c8..17638a029 100644
--- a/src/main/java/net/openhft/chronicle/hash/replication/EngineReplicationLangBytesConsumer.java
+++ b/src/main/java/net/openhft/chronicle/hash/replication/EngineReplicationLangBytesConsumer.java
@@ -1,11 +1,12 @@
 package net.openhft.chronicle.hash.replication;
 
 import net.openhft.chronicle.map.EngineReplicationLangBytes;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * Created by Rob Austin
  */
 public interface EngineReplicationLangBytesConsumer {
 
-    void set(EngineReplicationLangBytes engineReplicationLangBytes);
+    void set(@NotNull EngineReplicationLangBytes engineReplicationLangBytes);
 }