diff --git a/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java b/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java
index e134f0418..2740a19a5 100755
--- a/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java
+++ b/src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java
@@ -64,6 +64,7 @@ import static java.lang.Math.max;
 import static java.lang.Thread.currentThread;
 import static java.nio.ByteBuffer.allocateDirect;
 import static net.openhft.chronicle.map.Asserts.assertNotNull;
+import static net.openhft.chronicle.map.XStreamHelper.to$$Native;
 import static net.openhft.lang.MemoryUnit.*;
 
 class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
@@ -862,7 +863,7 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
                         case "chronicle-key":
 
                             if (kClass.getCanonicalName().startsWith("net.openhft.lang.values")) {
-                                return to$$Native(reader, vClass, true);
+                                return to$$Native(reader, vClass, true, VanillaChronicleMap.this);
                             } else {
                                 long keySize = keySizeMarshaller.readSize(buffer);
                                 ThreadLocalCopies copies = keyReaderProvider.getCopies(null);
@@ -872,7 +873,7 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
                         case "chronicle-value":
 
                             if (vClass.getCanonicalName().startsWith("net.openhft.lang.values")) {
-                                return to$$Native(reader, vClass, false);
+                                return to$$Native(reader, vClass, false, VanillaChronicleMap.this);
                             } else {
                                 long valueSize = valueSizeMarshaller.readSize(buffer);
                                 ThreadLocalCopies copies = valueReaderProvider.getCopies(null);
@@ -904,51 +905,7 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, ? super KI>,
                     } else return (E) unmarshallingContext.convertAnother(null, clazz);
                 }
 
-                private Object to$$Native(HierarchicalStreamReader reader, final Class aClass, final boolean isKey) {
 
-                    final Object o = isKey ? newKeyInstance() : newValueInstance();
-                    try {
-                        for (Method $$nativeMethod : o.getClass().getMethods()) {
-                            if ($$nativeMethod.getName().equals("setValue") && $$nativeMethod.getParameterTypes()
-                                    .length == 1) {
-
-                                Class<?> parameterType = $$nativeMethod.getParameterTypes()[0];
-                                String value = reader.getValue();
-
-
-                                if (parameterType.isPrimitive()) {
-
-                                    // convert the primitive to their boxed type
-
-                                    if (parameterType == int.class)
-                                        parameterType = Integer.class;
-                                    else if (parameterType == char.class)
-                                        parameterType = Character.class;
-                                    else {
-                                        final String name = parameterType.getSimpleName();
-
-                                        final String properName = "java.lang." + Character.toString
-                                                (name.charAt(0)).toUpperCase()
-                                                + name.substring(1);
-                                        parameterType = Class.forName(properName);
-                                    }
-                                }
-
-
-                                final Method valueOf = parameterType.getMethod("valueOf", String.class);
-                                final Object invoke = valueOf.invoke(null, value);
-                                $$nativeMethod.invoke(o, invoke);
-                                return o;
-
-                            }
-                        }
-                    } catch (Exception e) {
-                        throw new ConversionException("class=" + aClass.getCanonicalName(), e);
-                    }
-                    throw new ConversionException("setValue(..) method not found in class=" + aClass
-                            .getCanonicalName
-                                    ());
-                }
             };
 
             xstream.registerConverter(converter);
diff --git a/src/main/java/net/openhft/chronicle/map/XStreamHelper.java b/src/main/java/net/openhft/chronicle/map/XStreamHelper.java
new file mode 100644
index 000000000..db6b3fe8f
--- /dev/null
+++ b/src/main/java/net/openhft/chronicle/map/XStreamHelper.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2014 Higher Frequency Trading http://www.higherfrequencytrading.com
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.openhft.chronicle.map;
+
+import com.thoughtworks.xstream.converters.ConversionException;
+import com.thoughtworks.xstream.io.HierarchicalStreamReader;
+
+import java.lang.reflect.Method;
+
+/**
+ * Created by Rob on 18/12/14.
+ */
+class XStreamHelper {
+
+    static Object to$$Native(HierarchicalStreamReader reader, final Class aClass, final boolean isKey, ChronicleMap map) {
+
+
+        final Object o = isKey ? map.newKeyInstance() : map.newValueInstance();
+        try {
+            for (Method $$nativeMethod : o.getClass().getMethods()) {
+                if ($$nativeMethod.getName().equals("setValue") && $$nativeMethod.getParameterTypes()
+                        .length == 1) {
+
+                    Class<?> parameterType = $$nativeMethod.getParameterTypes()[0];
+                    String value = reader.getValue();
+
+
+                    if (parameterType.isPrimitive()) {
+
+                        // convert the primitive to their boxed type
+
+                        if (parameterType == int.class)
+                            parameterType = Integer.class;
+                        else if (parameterType == char.class)
+                            parameterType = Character.class;
+                        else {
+                            final String name = parameterType.getSimpleName();
+
+                            final String properName = "java.lang." + Character.toString
+                                    (name.charAt(0)).toUpperCase()
+                                    + name.substring(1);
+                            parameterType = Class.forName(properName);
+                        }
+                    }
+
+
+                    final Method valueOf = parameterType.getMethod("valueOf", String.class);
+                    final Object invoke = valueOf.invoke(null, value);
+                    $$nativeMethod.invoke(o, invoke);
+                    return o;
+
+                }
+            }
+        } catch (Exception e) {
+            throw new ConversionException("class=" + aClass.getCanonicalName(), e);
+        }
+        throw new ConversionException("setValue(..) method not found in class=" + aClass
+                .getCanonicalName
+                        ());
+    }
+}