diff --git a/src/main/java/net/openhft/chronicle/map/ChronicleMapBuilder.java b/src/main/java/net/openhft/chronicle/map/ChronicleMapBuilder.java
index 110fbbc2f..83195af85 100755
--- a/src/main/java/net/openhft/chronicle/map/ChronicleMapBuilder.java
+++ b/src/main/java/net/openhft/chronicle/map/ChronicleMapBuilder.java
@@ -166,7 +166,6 @@ public final class ChronicleMapBuilder<K, V> implements
     private long entries = -1L;
     private long lockTimeOut = 20000L;
     private TimeUnit lockTimeOutUnit = TimeUnit.MILLISECONDS;
-    private int metaDataBytes = 0;
     private double maxBloatFactor = 1.0;
     private boolean allowSegmentTiering = true;
     private double nonTieredSegmentsPercentile = 0.99999;
@@ -538,7 +537,7 @@ public final class ChronicleMapBuilder<K, V> implements
     }
 
     private EntrySizeInfo entrySizeInfo() {
-        double size = metaDataBytes;
+        double size = 0;
         double keySize = averageKeySize();
         size += averageSizeEncodingSize(keyBuilder, keySize);
         size += keySize;
@@ -1070,18 +1069,6 @@ public final class ChronicleMapBuilder<K, V> implements
         return removeReturnsNull;
     }
 
-    // hidden for initial release.
-    ChronicleMapBuilder<K, V> metaDataBytes(int metaDataBytes) {
-        if (metaDataBytes < 0 || metaDataBytes > 255)
-            throw new IllegalArgumentException("MetaDataBytes must be [0..255] was " + metaDataBytes);
-        this.metaDataBytes = metaDataBytes;
-        return this;
-    }
-
-    int metaDataBytes() {
-        return metaDataBytes;
-    }
-
     @Override
     public ChronicleMapBuilder<K, V> maxBloatFactor(double maxBloatFactor) {
         if (isNaN(maxBloatFactor) || maxBloatFactor < 1.0 || maxBloatFactor > 1_000.0) {
@@ -1136,7 +1123,6 @@ public final class ChronicleMapBuilder<K, V> implements
                 ", valueAlignment=" + valueAlignment() +
                 ", entries=" + entries() +
                 ", lockTimeOut=" + lockTimeOut + " " + lockTimeOutUnit +
-                ", metaDataBytes=" + metaDataBytes() +
                 ", putReturnsNull=" + putReturnsNull() +
                 ", removeReturnsNull=" + removeReturnsNull() +
                 ", timeProvider=" + timeProvider() +
diff --git a/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java b/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java
index 3dac111ec..870eca3d8 100755
--- a/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java
+++ b/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java
@@ -72,10 +72,6 @@ public class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super
     public transient Provider<BytesReader<V>> valueReaderProvider;
     public transient Provider<VI> valueInteropProvider;
 
-    /////////////////////////////////////////////////
-    // Event listener and meta data
-    public final int metaDataBytes;
-
     /////////////////////////////////////////////////
     // Memory management and dependent fields
     public final Alignment alignment;
@@ -122,9 +118,6 @@ public class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super
 
         constantlySizedEntry = builder.constantlySizedEntries();
 
-        // Event listener and meta data
-        metaDataBytes = builder.metaDataBytes();
-
         // Concurrency (number of segments), memory management and dependent fields
         alignment = builder.valueAlignment();
         worstAlignment = builder.worstAlignment();
diff --git a/src/main/java/net/openhft/chronicle/map/impl/stage/entry/MapEntryStages.java b/src/main/java/net/openhft/chronicle/map/impl/stage/entry/MapEntryStages.java
index 351fd53d1..3a900bffb 100644
--- a/src/main/java/net/openhft/chronicle/map/impl/stage/entry/MapEntryStages.java
+++ b/src/main/java/net/openhft/chronicle/map/impl/stage/entry/MapEntryStages.java
@@ -233,8 +233,7 @@ public abstract class MapEntryStages<K, V> extends HashEntryStages<K>
     }
 
     long sizeOfEverythingBeforeValue(long keySize, long valueSize) {
-        return mh.m().metaDataBytes +
-                mh.m().keySizeMarshaller.sizeEncodingSize(keySize) + keySize +
+        return mh.m().keySizeMarshaller.sizeEncodingSize(keySize) + keySize +
                 mh.m().valueSizeMarshaller.sizeEncodingSize(valueSize);
     }