diff --git a/common/sourceTest/java/ch/systemsx/cisd/common/compression/file/CompressionWorkerTest.java b/common/sourceTest/java/ch/systemsx/cisd/common/compression/file/CompressionWorkerTest.java
index 66ef69a1fab233144d86346e5e4a5807b8863b97..af3529787be1ab7c95aa55a0887351e0bc54b844 100644
--- a/common/sourceTest/java/ch/systemsx/cisd/common/compression/file/CompressionWorkerTest.java
+++ b/common/sourceTest/java/ch/systemsx/cisd/common/compression/file/CompressionWorkerTest.java
@@ -35,6 +35,7 @@ import org.testng.annotations.AfterMethod;
 import org.testng.annotations.BeforeMethod;
 import org.testng.annotations.Test;
 
+import ch.rinn.restrictions.Friend;
 import ch.systemsx.cisd.common.exceptions.Status;
 import ch.systemsx.cisd.common.exceptions.StatusFlag;
 import ch.systemsx.cisd.common.logging.BufferedAppender;
@@ -45,6 +46,7 @@ import ch.systemsx.cisd.common.logging.LogInitializer;
  * 
  * @author Bernd Rinn
  */
+@Friend(toClasses = CompressionWorker.class)
 public final class CompressionWorkerTest
 {
     private Mockery context;