diff --git a/fine-kryo/src/com/fr/third/org/objenesis/ObjenesisBase.java b/fine-kryo/src/com/fr/third/org/objenesis/ObjenesisBase.java
index 2d4b2209f..2d08272c3 100644
--- a/fine-kryo/src/com/fr/third/org/objenesis/ObjenesisBase.java
+++ b/fine-kryo/src/com/fr/third/org/objenesis/ObjenesisBase.java
@@ -18,6 +18,7 @@ package com.fr.third.org.objenesis;
 import com.fr.third.org.objenesis.instantiator.ObjectInstantiator;
 import com.fr.third.org.objenesis.strategy.InstantiatorStrategy;
 
+import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
 /**
@@ -28,11 +29,15 @@ import java.util.concurrent.ConcurrentHashMap;
  */
 public class ObjenesisBase implements Objenesis {
 
-   /** Strategy used by this Objenesi implementation to create classes */
+   /**
+    * Strategy used by this Objenesi implementation to create classes
+    */
    protected final InstantiatorStrategy strategy;
 
-   /** Strategy cache. Key = Class, Value = InstantiatorStrategy */
-   protected ConcurrentHashMap<String, ObjectInstantiator<?>> cache;
+   /**
+    * Strategy cache. Key = Class, Value = InstantiatorStrategy
+    */
+   protected Map<Class, ObjectInstantiator<?>> cache;
 
    /**
     * Constructor allowing to pick a strategy and using cache
@@ -50,17 +55,17 @@ public class ObjenesisBase implements Objenesis {
     * @param useCache If {@link ObjectInstantiator}s should be cached
     */
    public ObjenesisBase(InstantiatorStrategy strategy, boolean useCache) {
-      if(strategy == null) {
+      if (strategy == null) {
          throw new IllegalArgumentException("A strategy can't be null");
       }
       this.strategy = strategy;
-      this.cache = useCache ? new ConcurrentHashMap<String, ObjectInstantiator<?>>() : null;
+      this.cache = useCache ? new ConcurrentHashMap<Class, ObjectInstantiator<?>>() : null;
    }
 
    @Override
    public String toString() {
       return getClass().getName() + " using " + strategy.getClass().getName()
-         + (cache == null ? " without" : " with") + " caching";
+              + (cache == null ? " without" : " with") + " caching";
    }
 
    /**
@@ -83,20 +88,29 @@ public class ObjenesisBase implements Objenesis {
     */
    @SuppressWarnings("unchecked")
    public <T> ObjectInstantiator<T> getInstantiatorOf(Class<T> clazz) {
-      if(clazz.isPrimitive()) {
+      if (clazz.isPrimitive()) {
          throw new IllegalArgumentException("Primitive types can't be instantiated in Java");
       }
-      if(cache == null) {
+      if (cache == null) {
          return strategy.newInstantiatorOf(clazz);
       }
-      ObjectInstantiator<?> instantiator = cache.get(clazz.getName());
-      if(instantiator == null) {
+      ObjectInstantiator<?> instantiator = cache.get(clazz);
+      if (instantiator == null) {
          ObjectInstantiator<?> newInstantiator = strategy.newInstantiatorOf(clazz);
-         instantiator = cache.putIfAbsent(clazz.getName(), newInstantiator);
-         if(instantiator == null) {
+         instantiator = putIfAbsent(clazz, newInstantiator);
+         if (instantiator == null) {
             instantiator = newInstantiator;
          }
       }
       return (ObjectInstantiator<T>) instantiator;
    }
-}
+
+   private ObjectInstantiator<?> putIfAbsent(Class key, ObjectInstantiator<?> newInstantiator) {
+
+      ObjectInstantiator<?> instantiator = cache.get(key);
+      if (instantiator == null) {
+         instantiator = cache.put(key, newInstantiator);
+      }
+      return instantiator;
+   }
+}
\ No newline at end of file