diff --git a/image_readers/source/java/ch/systemsx/cisd/imagereaders/ImageReaderFactory.java b/image_readers/source/java/ch/systemsx/cisd/imagereaders/ImageReaderFactory.java
index 1ad1dc7e4ce89716ba02c3e6cae7de299ad946a9..2dc610095c64165761e1daf2f490cb76a10cd6f2 100644
--- a/image_readers/source/java/ch/systemsx/cisd/imagereaders/ImageReaderFactory.java
+++ b/image_readers/source/java/ch/systemsx/cisd/imagereaders/ImageReaderFactory.java
@@ -128,4 +128,12 @@ public class ImageReaderFactory
     {
         libraries = newLibraries;
     }
+    
+    /**
+     * used only for testing purposes.
+     */
+    static List<IImageReaderLibrary> getLibraries()
+    {
+        return libraries;
+    }
 }
diff --git a/image_readers/sourceTest/java/ch/systemsx/cisd/imagereaders/ImageReaderFactoryTest.java b/image_readers/sourceTest/java/ch/systemsx/cisd/imagereaders/ImageReaderFactoryTest.java
index 8c1cd3db5b4970b5d1c5c656af85010f06ed592a..39dbba5c1ee0c2af59fc85868c798211c349c7e3 100644
--- a/image_readers/sourceTest/java/ch/systemsx/cisd/imagereaders/ImageReaderFactoryTest.java
+++ b/image_readers/sourceTest/java/ch/systemsx/cisd/imagereaders/ImageReaderFactoryTest.java
@@ -90,11 +90,12 @@ public class ImageReaderFactoryTest extends ImageReaderTestCase
     }
 
     @Test(expectedExceptions = IOExceptionUnchecked.class)
-    public void testReadNonExistingFile()
+    public void testReadNonExistingFile() throws Exception
     {
         final String invalidName = "invalid_file_path.jpg";
         final File invalidFile = new File(invalidName);
 
+        ImageReadersTestHelper.setUpLibraries(ImageReaderConstants.BIOFORMATS_LIBRARY);
         IImageReader reader =
                 ImageReaderFactory.tryGetReaderForFile(BIOFORMATS_LIBRARY, invalidName);
         reader.readImage(invalidFile, ImageID.NULL, null);
diff --git a/image_readers/sourceTest/java/ch/systemsx/cisd/imagereaders/ImageReaderTestCase.java b/image_readers/sourceTest/java/ch/systemsx/cisd/imagereaders/ImageReaderTestCase.java
index a1de7fb5c6d28886313c468ce899129a6c140a2e..526a67a59759197d65d2a076966c28f51426e24d 100644
--- a/image_readers/sourceTest/java/ch/systemsx/cisd/imagereaders/ImageReaderTestCase.java
+++ b/image_readers/sourceTest/java/ch/systemsx/cisd/imagereaders/ImageReaderTestCase.java
@@ -17,8 +17,11 @@
 package ch.systemsx.cisd.imagereaders;
 
 import java.io.File;
+import java.util.List;
 
 import org.testng.AssertJUnit;
+import org.testng.annotations.AfterMethod;
+import org.testng.annotations.BeforeMethod;
 
 /**
  * Common super class for unit test using example image files.
@@ -34,6 +37,19 @@ public abstract class ImageReaderTestCase extends AssertJUnit
 
     protected static final String INVALID_SUBDIR = "invalid";
 
+    private List<IImageReaderLibrary> libraries;
+    
+    @BeforeMethod
+    public void setUp()
+    {
+        libraries = ImageReaderFactory.getLibraries();
+    }
+
+    @AfterMethod
+    public void tearDown()
+    {
+        ImageReaderFactory.setLibraries(libraries);
+    }
 
     protected File getImageFileForLibrary(String libraryName, String fileName)
     {