diff --git a/src/main/java/net/openhft/chronicle/map/MapEventListener.java b/src/main/java/net/openhft/chronicle/map/MapEventListener.java
index 90bfa492c..51215d8d7 100644
--- a/src/main/java/net/openhft/chronicle/map/MapEventListener.java
+++ b/src/main/java/net/openhft/chronicle/map/MapEventListener.java
@@ -137,6 +137,15 @@ public abstract class MapEventListener<K, V> implements Serializable {
         return true;
     }
 
+    /**
+     * This performs an early check to see if the values will be consumed or discarded.
+     *
+     * @return true unless you know the event won't be needed.
+     */
+    public boolean usesValue() {
+        return true;
+    }
+
     private static class LoggingMapEventListener extends MapEventListener {
         public final static Logger LOGGER = LoggerFactory.getLogger(LoggingMapEventListener.class);
         private static final long serialVersionUID = 0L;
diff --git a/src/main/java/net/openhft/chronicle/map/ReplicatedChronicleMap.java b/src/main/java/net/openhft/chronicle/map/ReplicatedChronicleMap.java
index 21be35531..3d1af9d9e 100755
--- a/src/main/java/net/openhft/chronicle/map/ReplicatedChronicleMap.java
+++ b/src/main/java/net/openhft/chronicle/map/ReplicatedChronicleMap.java
@@ -959,7 +959,7 @@ final class ReplicatedChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? supe
                                 replacedTimestamp, this);
                     }
                     if (eventListener != null && eventListener.isActive()) {
-                        V valueInstance = toValue.toInstance(copies, v, valueSize);
+                        V valueInstance = eventListener.usesValue() ? toValue.toInstance(copies, v, valueSize) : null;
                         writeUnlock();
                         // TODO unlocking is dangerous, because this method is a part of
                         // acquireUsingLocked()
@@ -1184,7 +1184,7 @@ final class ReplicatedChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? supe
                     }
                     if (eventListener != null && eventListener.isActive()) {
                         final K key1 = toKey.toInstance(copies, key, keySize);
-                        final V newValue = toValue.toInstance(copies, value, valueSize);
+                        final V newValue = eventListener.usesValue() ? toValue.toInstance(copies, value, valueSize) : null;
 
                         writeUnlock();
                         try {
@@ -1227,7 +1227,7 @@ final class ReplicatedChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? supe
                     byte replacedIdentifier = 0;
                     long replacedTimestamp = 0;
                     final K key1 = toKey.toInstance(copies, key, keySize);
-                    final V newValue = toValue.toInstance(copies, value, valueSize);
+                    final V newValue = eventListener.usesValue() ? toValue.toInstance(copies, value, valueSize) : null;
                     writeUnlock();
                     try {
                         eventListener.onPut(key1,
@@ -1352,7 +1352,7 @@ final class ReplicatedChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? supe
                 byte replacedIdentifier = 0;
                 long replacedTimestamp = 0;
                 final K key1 = toKey.toInstance(copies, key, keySize);
-                final V newValue = toValue.toInstance(copies, value, valueSize);
+                final V newValue = eventListener.usesValue() ? toValue.toInstance(copies, value, valueSize) : null;
                 writeUnlock();
                 try {
                     eventListener.onPut(key1,
diff --git a/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java b/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java
index 79a85936a..406399363 100755
--- a/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java
+++ b/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java
@@ -2123,7 +2123,7 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
                 byte replacedIdentifier = (byte) 0;
                 long replacedTimeStamp = 0;
                 final K key1 = toKey.toInstance(copies, key, keySize);
-                final V newValue = toValue.toInstance(copies, v, valueSize);
+                final V newValue = eventListener.usesValue() ? toValue.toInstance(copies, v, valueSize) : null;
                 writeUnlock();
                 // TODO unlocking here is dangerous, because this method is a part of
                 // acquireUsingLocked(), after which lock assumed to be valid
@@ -2161,7 +2161,7 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
             }
             if (eventListener != null && eventListener.isActive()) {
                 eventListener.onGetFound(toKey.toInstance(copies, key, keySize),
-                        toValue.toInstance(copies, v, valueSize));
+                        eventListener.usesValue() ? toValue.toInstance(copies, v, valueSize) : null);
             }
 
             return v;
@@ -2234,7 +2234,7 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
                         );
                     if (eventListener != null && eventListener.isActive()) {
                         final K key1 = toKey.toInstance(copies, key, keySize);
-                        final V newValue = toValue.toInstance(copies, value, valueSize);
+                        final V newValue = eventListener.usesValue() ? toValue.toInstance(copies, value, valueSize) : null;
                         writeUnlock();
                         try {
                             eventListener.onPut(key1,
@@ -2270,7 +2270,7 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
                     byte replacedIdentifier = 0;
                     long replacedTimeStamp = 0;
                     final K key1 = toKey.toInstance(copies, key, keySize);
-                    final V newValue = toValue.toInstance(copies, value, valueSize);
+                    final V newValue = eventListener.usesValue() ? toValue.toInstance(copies, value, valueSize) : null;
 
                     writeUnlock();
                     try {
@@ -2383,7 +2383,7 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
                         segmentState.identifier, (byte) 0, segmentState.timestamp, 0, this);
             if (eventListener != null && eventListener.isActive()) {
                 final K key1 = toKey.toInstance(copies, key, keySize);
-                final V newValue = toValue.toInstance(copies, value, valueSize);
+                final V newValue = eventListener.usesValue() ? toValue.toInstance(copies, value, valueSize) : null;
                 writeUnlock();
                 try {
                     eventListener.onPut(key1,
@@ -2428,7 +2428,7 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
                 entry.positionAddr(valueAddr);
                 prevValueInstance = null;
                 if (!putReturnsNull)
-                    prevValueInstance = readValue(copies, entry, null, prevValueSize);
+                    prevValueInstance = eventListener.usesValue() ? readValue(copies, entry, null, prevValueSize) : null;
             }
 
             boolean doPutValue;
@@ -2466,7 +2466,7 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
                         segmentState.timestamp, replacedTimestamp, this);
             if (eventListener != null && eventListener.isActive()) {
                 final K key1 = toKey.toInstance(copies, key, keySize);
-                final V newValue = toValue.toInstance(copies, value, valueSize);
+                final V newValue = eventListener.usesValue() ? toValue.toInstance(copies, value, valueSize) : null;
 
                 writeUnlock();
                 try {
@@ -2714,6 +2714,7 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
             RV removedValue = null;
             if ((!booleanResult && !resultUnused) || (eventListener != null && eventListener.isActive())) {
                 // todo reuse some value
+                // todo check eventListener.usesValue()
                 removedValue = readValue.readValue(copies, entry, null, valueSize);
                 entry.position(entry.position() - valueSize);
             }
@@ -2735,8 +2736,8 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
                         segmentState.identifier, replacedIdentifier,
                         segmentState.timestamp, replacedTimestamp, this);
             if (eventListener != null && eventListener.isActive()) {
-                V removedValueForEventListener =
-                        toValue.toInstance(copies, removedValue, valueSize);
+                V removedValueForEventListener = eventListener.usesValue() ?
+                        toValue.toInstance(copies, removedValue, valueSize) : null;
 
                 final K key1 = toKey.toInstance(copies, key, keySize);
                 writeUnlock();
@@ -2913,8 +2914,8 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
             }
             if (eventListener != null && eventListener.isActive()) {
                 final K key1 = toKey.toInstance(copies, key, keySize);
-                final V newValue1 = toValue.toInstance(copies, newValue, newValueSize);
-                final V replacedValue = toValue.toInstance(copies, prevValue, valueSize);
+                final V newValue1 = eventListener.usesValue() ? toValue.toInstance(copies, newValue, newValueSize) : null;
+                final V replacedValue = eventListener.usesValue() ? toValue.toInstance(copies, prevValue, valueSize) : null;
                 writeUnlock();
                 try {
                     eventListener.onPut(key1,