diff --git a/src/main/java/net/openhft/chronicle/hash/locks/IllegalInterProcessLockStateException.java b/src/main/java/net/openhft/chronicle/hash/locks/IllegalInterProcessLockStateException.java
index f29a0565e..ab79bd479 100644
--- a/src/main/java/net/openhft/chronicle/hash/locks/IllegalInterProcessLockStateException.java
+++ b/src/main/java/net/openhft/chronicle/hash/locks/IllegalInterProcessLockStateException.java
@@ -16,7 +16,7 @@
 
 package net.openhft.chronicle.hash.locks;
 
-public class IllegalInterProcessLockStateException extends IllegalMonitorStateException {
+public final class IllegalInterProcessLockStateException extends IllegalMonitorStateException {
     private static final long serialVersionUID = 0L;
     public IllegalInterProcessLockStateException(String s) {
         super(s);
diff --git a/src/main/java/net/openhft/chronicle/hash/serialization/ListMarshaller.java b/src/main/java/net/openhft/chronicle/hash/serialization/ListMarshaller.java
index f13e393a9..2e4183f3d 100644
--- a/src/main/java/net/openhft/chronicle/hash/serialization/ListMarshaller.java
+++ b/src/main/java/net/openhft/chronicle/hash/serialization/ListMarshaller.java
@@ -57,7 +57,7 @@ import static net.openhft.chronicle.hash.serialization.StatefulCopyable.copyIfNe
  * @see SetMarshaller
  * @see MapMarshaller
  */
-public class ListMarshaller<T>
+public final class ListMarshaller<T>
         implements BytesReader<List<T>>, BytesWriter<List<T>>, StatefulCopyable<ListMarshaller<T>> {
 
     // Config fields
diff --git a/src/main/java/net/openhft/chronicle/hash/serialization/MapMarshaller.java b/src/main/java/net/openhft/chronicle/hash/serialization/MapMarshaller.java
index 31be76714..ec1ef01e7 100644
--- a/src/main/java/net/openhft/chronicle/hash/serialization/MapMarshaller.java
+++ b/src/main/java/net/openhft/chronicle/hash/serialization/MapMarshaller.java
@@ -50,7 +50,7 @@ import static net.openhft.chronicle.hash.serialization.StatefulCopyable.copyIfNe
  * @see ListMarshaller
  * @see SetMarshaller
  */
-public class MapMarshaller<K, V>
+public final class MapMarshaller<K, V>
         implements BytesReader<Map<K, V>>, BytesWriter<Map<K, V>>,
         StatefulCopyable<MapMarshaller<K, V>> {
 
diff --git a/src/main/java/net/openhft/chronicle/hash/serialization/SetMarshaller.java b/src/main/java/net/openhft/chronicle/hash/serialization/SetMarshaller.java
index 1dd6fa265..7c6d69dd9 100644
--- a/src/main/java/net/openhft/chronicle/hash/serialization/SetMarshaller.java
+++ b/src/main/java/net/openhft/chronicle/hash/serialization/SetMarshaller.java
@@ -58,7 +58,7 @@ import static net.openhft.chronicle.hash.serialization.StatefulCopyable.copyIfNe
  * @see ListMarshaller
  * @see MapMarshaller
  */
-public class SetMarshaller<T>
+public final class SetMarshaller<T>
         implements BytesReader<Set<T>>, BytesWriter<Set<T>>, StatefulCopyable<SetMarshaller<T>> {
 
     // Config fields