diff --git a/scm-core/src/main/java/sonia/scm/io/DeepCopy.java b/scm-core/src/main/java/sonia/scm/io/DeepCopy.java
index 0db3da01aa..a349b842fe 100644
--- a/scm-core/src/main/java/sonia/scm/io/DeepCopy.java
+++ b/scm-core/src/main/java/sonia/scm/io/DeepCopy.java
@@ -30,8 +30,13 @@
  */
 
 
+
 package sonia.scm.io;
 
+//~--- non-JDK imports --------------------------------------------------------
+
+import com.google.common.io.Closer;
+
 //~--- JDK imports ------------------------------------------------------------
 
 import java.io.IOException;
@@ -69,12 +74,15 @@ public final class DeepCopy
   {
     T obj = null;
 
+    Closer closer = Closer.create();
+
     try
     {
 
       // Write the object out to a byte array
-      FastByteArrayOutputStream fbos = new FastByteArrayOutputStream();
-      ObjectOutputStream out = new ObjectOutputStream(fbos);
+      FastByteArrayOutputStream fbos =
+        closer.register(new FastByteArrayOutputStream());
+      ObjectOutputStream out = closer.register(new ObjectOutputStream(fbos));
 
       out.writeObject(orig);
       out.flush();
@@ -82,7 +90,10 @@ public final class DeepCopy
 
       // Retrieve an input stream from the byte array and read
       // a copy of the object back in.
-      ObjectInputStream in = new ObjectInputStream(fbos.getInputStream());
+      // use ScmObjectInputStream to solve ClassNotFoundException
+      // for plugin classes
+      ObjectInputStream in =
+        closer.register(new ScmObjectInputStream(fbos.getInputStream()));
 
       obj = (T) in.readObject();
     }
@@ -90,6 +101,10 @@ public final class DeepCopy
     {
       throw new IOException("could not copy object", ex);
     }
+    finally
+    {
+      closer.close();
+    }
 
     return obj;
   }
diff --git a/scm-core/src/main/java/sonia/scm/io/ScmObjectInputStream.java b/scm-core/src/main/java/sonia/scm/io/ScmObjectInputStream.java
new file mode 100644
index 0000000000..603ac61c11
--- /dev/null
+++ b/scm-core/src/main/java/sonia/scm/io/ScmObjectInputStream.java
@@ -0,0 +1,123 @@
+/**
+ * Copyright (c) 2010, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm.io;
+
+//~--- non-JDK imports --------------------------------------------------------
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+//~--- JDK imports ------------------------------------------------------------
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.ObjectInputStream;
+import java.io.ObjectStreamClass;
+
+/**
+ * {@link ObjectInputStream} implementation which uses the context class loader 
+ * to resolve classes.
+ *
+ * @author Sebastian Sdorra
+ * @since 1.36
+ */
+public class ScmObjectInputStream extends ObjectInputStream
+{
+
+  /**
+   * the logger for ScmObjectInputStream
+   */
+  private static final Logger logger =
+    LoggerFactory.getLogger(ScmObjectInputStream.class);
+
+  //~--- constructors ---------------------------------------------------------
+
+  /**
+   * {@inheritDoc}
+   */
+  public ScmObjectInputStream(InputStream stream) throws IOException
+  {
+    super(stream);
+  }
+
+  //~--- methods --------------------------------------------------------------
+
+  /**
+   * {@inheritDoc}
+   */
+  @Override
+  protected Class<?> resolveClass(ObjectStreamClass desc)
+    throws IOException, ClassNotFoundException
+  {
+    Class<?> clazz = null;
+    ClassLoader classLoader = getClassLoader();
+
+    try
+    {
+      clazz = classLoader.loadClass(desc.getName());
+    }
+    catch (ClassNotFoundException ex)
+    {
+      logger.warn("could not find class ".concat(desc.getName()), ex);
+    }
+
+    if (clazz == null)
+    {
+      clazz = super.resolveClass(desc);
+    }
+
+    return clazz;
+  }
+
+  //~--- get methods ----------------------------------------------------------
+
+  /**
+   * Returns the context class loader if available. If the context class loader
+   * is not available the method will fall back to the class loader which has
+   * load this class.
+   *
+   *
+   * @return context class loader or default class loader
+   */
+  private ClassLoader getClassLoader()
+  {
+    ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+
+    if (classLoader == null)
+    {
+      logger.debug("could not find context class loader, fall back to default");
+      classLoader = ScmObjectInputStream.class.getClassLoader();
+    }
+
+    return classLoader;
+  }
+}