diff --git a/source/test-java/org/alfresco/repo/content/metadata/PdfBoxMetadataExtracterTest.java b/source/test-java/org/alfresco/repo/content/metadata/PdfBoxMetadataExtracterTest.java
index 7a0e1682e7..133bc3b7a8 100644
--- a/source/test-java/org/alfresco/repo/content/metadata/PdfBoxMetadataExtracterTest.java
+++ b/source/test-java/org/alfresco/repo/content/metadata/PdfBoxMetadataExtracterTest.java
@@ -23,41 +23,44 @@
  * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
  * #L%
  */
-package org.alfresco.repo.content.metadata;
-
+package org.alfresco.repo.content.metadata;
+
 import java.io.File;
 import java.io.FileNotFoundException;
-import java.io.Serializable;
-import java.util.Calendar;
+import java.io.Serializable;
+import java.util.Calendar;
 import java.util.HashMap;
-import java.util.Map;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 
-import org.alfresco.model.ContentModel;
-import org.alfresco.repo.content.MimetypeMap;
+import org.alfresco.model.ContentModel;
+import org.alfresco.repo.content.MimetypeMap;
 import org.alfresco.repo.content.transform.AbstractContentTransformerTest;
-import org.alfresco.service.cmr.repository.datatype.DefaultTypeConverter;
-import org.alfresco.service.namespace.QName;
-import org.apache.pdfbox.util.DateConverter;
-
-/**
- * @see org.alfresco.repo.content.metadata.PdfBoxMetadataExtracter
- * 
- * @author Jesper Steen Møller
- */
-public class PdfBoxMetadataExtracterTest extends AbstractMetadataExtracterTest
-{
+import org.alfresco.service.cmr.repository.datatype.DefaultTypeConverter;
+import org.alfresco.service.namespace.QName;
+import org.apache.pdfbox.util.DateConverter;
+
+/**
+ * @see org.alfresco.repo.content.metadata.PdfBoxMetadataExtracter
+ * 
+ * @author Jesper Steen Møller
+ */
+public class PdfBoxMetadataExtracterTest extends AbstractMetadataExtracterTest
+{
     private PdfBoxMetadataExtracter extracter;
     
     private static final int MAX_CONCURENT_EXTRACTIONS = 5;
-	private static final double MAX_DOC_SIZE_MB = 0.03;
-
-    @Override
-    public void setUp() throws Exception
-    {
-        super.setUp();
-        extracter = new PdfBoxMetadataExtracter();
+	private static final double MAX_DOC_SIZE_MB = 0.03;
+
+    @Override
+    public void setUp() throws Exception
+    {
+        super.setUp();
+        extracter = new PdfBoxMetadataExtracter();
         extracter.setDictionaryService(dictionaryService);
         
         MetadataExtracterLimits pdfLimit = new MetadataExtracterLimits();
@@ -66,96 +69,113 @@ public class PdfBoxMetadataExtracterTest extends AbstractMetadataExtracterTest
         Map<String,MetadataExtracterLimits> limits = new HashMap<>();
         limits.put(MimetypeMap.MIMETYPE_PDF,pdfLimit);
         
-        extracter.setMimetypeLimits(limits);
-        extracter.register();
-    }
-
-    /**
-     * @return Returns the same transformer regardless - it is allowed
-     */
-    protected MetadataExtracter getExtracter()
-    {
-        return extracter;
-    }
-
-    public void testSupports() throws Exception
-    {
-        for (String mimetype : PdfBoxMetadataExtracter.SUPPORTED_MIMETYPES)
-        {
-            boolean supports = extracter.isSupported(mimetype);
-            assertTrue("Mimetype should be supported: " + mimetype, supports);
-        }
-    }
-
-    public void testPdfExtraction() throws Exception
-    {
-        testExtractFromMimetype(MimetypeMap.MIMETYPE_PDF);
-    }
-    
-    /**
-     * This test method extracts metadata from an Adobe Illustrator file (which in recent versions is a pdf file).
-     * @since 3.5.0
-     */
-    public void testAiExtraction() throws Exception
-    {
-        testExtractFromMimetype(MimetypeMap.MIMETYPE_APPLICATION_ILLUSTRATOR);
-    }
-    
-    /**
-     * We can also return a created date
-     */
-    protected void testFileSpecificMetadata(String mimetype,
-         Map<QName, Serializable> properties) {
-       assertEquals(
-             "Property " + ContentModel.PROP_CREATED + " not found for mimetype " + mimetype,
-             "2005-05-26T19:52:58.000Z",
-             DefaultTypeConverter.INSTANCE.convert(String.class, properties.get(ContentModel.PROP_CREATED)));
-    }
-    
-    /**
-     * Test that will show when the workaround is in place.
-     */
-    public void testDateConversion() throws Exception {
-       Calendar c = DateConverter.toCalendar("D:20050526205258+01'00'");
-       assertEquals(2005, c.get(Calendar.YEAR));
-       assertEquals(05-1, c.get(Calendar.MONTH));
-       assertEquals(26, c.get(Calendar.DAY_OF_MONTH));
-       assertEquals(20, c.get(Calendar.HOUR_OF_DAY));
-       assertEquals(52, c.get(Calendar.MINUTE));
-       assertEquals(58, c.get(Calendar.SECOND));
-       //assertEquals(0, c.get(Calendar.MILLISECOND));
+        extracter.setMimetypeLimits(limits);
+        extracter.register();
+    }
+
+    /**
+     * @return Returns the same transformer regardless - it is allowed
+     */
+    protected MetadataExtracter getExtracter()
+    {
+        return extracter;
+    }
+
+    public void testSupports() throws Exception
+    {
+        for (String mimetype : PdfBoxMetadataExtracter.SUPPORTED_MIMETYPES)
+        {
+            boolean supports = extracter.isSupported(mimetype);
+            assertTrue("Mimetype should be supported: " + mimetype, supports);
+        }
+    }
+
+    public void testPdfExtraction() throws Exception
+    {
+        testExtractFromMimetype(MimetypeMap.MIMETYPE_PDF);
+    }
+    
+    /**
+     * This test method extracts metadata from an Adobe Illustrator file (which in recent versions is a pdf file).
+     * @since 3.5.0
+     */
+    public void testAiExtraction() throws Exception
+    {
+        testExtractFromMimetype(MimetypeMap.MIMETYPE_APPLICATION_ILLUSTRATOR);
+    }
+    
+    /**
+     * We can also return a created date
+     */
+    protected void testFileSpecificMetadata(String mimetype,
+         Map<QName, Serializable> properties) {
+       assertEquals(
+             "Property " + ContentModel.PROP_CREATED + " not found for mimetype " + mimetype,
+             "2005-05-26T19:52:58.000Z",
+             DefaultTypeConverter.INSTANCE.convert(String.class, properties.get(ContentModel.PROP_CREATED)));
+    }
+    
+    /**
+     * Test that will show when the workaround is in place.
+     */
+    public void testDateConversion() throws Exception {
+       Calendar c = DateConverter.toCalendar("D:20050526205258+01'00'");
+       assertEquals(2005, c.get(Calendar.YEAR));
+       assertEquals(05-1, c.get(Calendar.MONTH));
+       assertEquals(26, c.get(Calendar.DAY_OF_MONTH));
+       assertEquals(20, c.get(Calendar.HOUR_OF_DAY));
+       assertEquals(52, c.get(Calendar.MINUTE));
+       assertEquals(58, c.get(Calendar.SECOND));
+       //assertEquals(0, c.get(Calendar.MILLISECOND));
     }
     
     public void testConcurrentExtractions() throws InterruptedException
     {
-        int threadNum = 10;
-        final CountDownLatch extractionsCountDown = new CountDownLatch(threadNum);
+        int threadNum = 11;
+        Map<String, Boolean> threadResults = new ConcurrentHashMap<>();
         for (int i = 0; i < threadNum; i++)
         {
-            Thread t = new Thread(new Runnable()
+            new Thread(new Runnable()
             {
                 @Override
                 public void run()
                 {
                     try
                     {
-                        Map<QName, Serializable> properties = extractFromMimetype(MimetypeMap.MIMETYPE_PDF);
-                        if (!properties.isEmpty())
-                        {
-                            extractionsCountDown.countDown();
-                        }
+                        threadResults.put(Thread.currentThread().getName(),
+                                !extractFromMimetype(MimetypeMap.MIMETYPE_PDF).isEmpty());
                     }
                     catch (Exception e)
                     {
                         e.printStackTrace();
                     }
                 }
-            });
-            t.start();
+
+            }).start();
         }
-        extractionsCountDown.await(1000, TimeUnit.MILLISECONDS);
-        long rejectedExtractions = extractionsCountDown.getCount();
-        assertTrue("Wrong number of rejected extractions", rejectedExtractions == (threadNum - MAX_CONCURENT_EXTRACTIONS));
+        int numWaits = 100;
+        while (numWaits > 0)
+        {
+            Thread.sleep(50);
+            if (threadResults.size() == threadNum)
+            {
+                break;
+            }
+            numWaits--;
+        }
+        Map<Boolean, Integer> counted = new HashMap<>();
+        counted.put(Boolean.FALSE, 0);
+        counted.put(Boolean.TRUE, 0);
+        for (Boolean result : threadResults.values())
+        {
+            counted.put(result, counted.get(result)+1);
+        }
+        assertEquals("Wrong number of failed extractions.",
+                new Integer(threadNum - MAX_CONCURENT_EXTRACTIONS),
+                counted.get(Boolean.FALSE));
+        assertEquals("Wrong number of successful extractions.",
+                new Integer(MAX_CONCURENT_EXTRACTIONS),
+                counted.get(Boolean.TRUE));
     }
 
     public void testMaxDocumentSizeLimit() throws Exception
@@ -168,5 +188,5 @@ public class PdfBoxMetadataExtracterTest extends AbstractMetadataExtracterTest
         }
         Map<QName, Serializable> properties = extractFromFile(sourceFile, MimetypeMap.MIMETYPE_PDF);
         assertTrue(properties.isEmpty());
-    }
-}
+    }
+}