diff --git a/nuxeo-platform-web-common/pom.xml b/nuxeo-platform-web-common/pom.xml
index 59d47fafa..c909f3b06 100644
--- a/nuxeo-platform-web-common/pom.xml
+++ b/nuxeo-platform-web-common/pom.xml
@@ -112,7 +112,8 @@
     <dependency>
       <groupId>org.mockito</groupId>
       <artifactId>mockito-all</artifactId>
+      <scope>test</scope>
     </dependency>
   </dependencies>
 
-</project>
\ No newline at end of file
+</project>
diff --git a/nuxeo-platform-web-common/src/test/java/org/nuxeo/ecm/platform/ui/web/download/TestDownloadServlet.java b/nuxeo-platform-web-common/src/test/java/org/nuxeo/ecm/platform/ui/web/download/TestDownloadServlet.java
index d7e2efedc..4a1d48450 100644
--- a/nuxeo-platform-web-common/src/test/java/org/nuxeo/ecm/platform/ui/web/download/TestDownloadServlet.java
+++ b/nuxeo-platform-web-common/src/test/java/org/nuxeo/ecm/platform/ui/web/download/TestDownloadServlet.java
@@ -1,15 +1,29 @@
 package org.nuxeo.ecm.platform.ui.web.download;
 
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.atLeast;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.io.PrintWriter;
+import java.lang.reflect.Method;
 
-import org.junit.Test;
-import static org.junit.Assert.assertEquals;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
 
+import org.junit.Test;
+import org.nuxeo.ecm.core.api.Blob;
 import org.nuxeo.ecm.core.api.ClientException;
+import org.nuxeo.ecm.core.api.impl.blob.InputStreamBlob;
+import org.nuxeo.ecm.core.storage.sql.Binary;
+import org.nuxeo.ecm.core.storage.sql.coremodel.SQLBlob;
 import org.nuxeo.ecm.platform.ui.web.download.DownloadServlet.ByteRange;
+import org.nuxeo.ecm.platform.web.common.requestcontroller.filter.BufferingServletOutputStream;
 
 public class TestDownloadServlet {
 
@@ -70,4 +84,64 @@ public void testWriteStream() throws Exception {
         DownloadServlet.writeStream(in, out, range);
         assertEquals("world", out.toString());
     }
+    
+    @Test
+    public void testETagHeaderNone() throws Exception {
+        doTestETagHeader(null);
+    }
+    
+    @Test
+    public void testETagHeaderNotMatched() throws Exception {
+        doTestETagHeader(Boolean.FALSE);
+    }
+
+    @Test
+    public void testETagHeaderMatched() throws Exception {
+        doTestETagHeader(Boolean.TRUE);
+    }
+    
+    private void doTestETagHeader(Boolean match) throws Exception {
+        HttpServletRequest req = mock(HttpServletRequest.class);       
+        HttpServletResponse resp = mock(HttpServletResponse.class);
+        Binary binary = mock(Binary.class);
+        String s = "Hello, world!";
+        final byte[] bytes = s.getBytes();
+        InputStream in = new ByteArrayInputStream(bytes);
+        String digest = "12345";
+        String bogusDigest = "67890";
+        SQLBlob blob = new SQLBlob(binary, "myFile.txt", "text/plain", 
+        		"UTF-8", digest, bytes.length);
+        when(binary.getStream()).thenReturn(in);
+        when(binary.getDigest()).thenReturn(digest);
+        String ifNoneMatchHeader = null;
+        if (match != null) {
+            ifNoneMatchHeader = (match) ? getETag(digest) : getETag(bogusDigest); 
+        }
+        when(req.getHeader("If-None-Match")).thenReturn(ifNoneMatchHeader);
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        BufferingServletOutputStream sos = new BufferingServletOutputStream(baos);
+        PrintWriter printWriter = new PrintWriter(sos);
+        when(resp.getOutputStream()).thenReturn(sos);
+        when(resp.getWriter()).thenReturn(printWriter);
+        
+        DownloadServlet servlet = new DownloadServlet();
+        Method m = servlet.getClass().getDeclaredMethod("downloadBlob",	new Class[] 
+        		{HttpServletRequest.class, HttpServletResponse.class, 
+        		Blob.class, String.class});
+        m.setAccessible(true);
+        m.invoke(servlet, new Object[] {req, resp, blob, (String) null});
+
+        verify(req, atLeast(1)).getHeader("If-None-Match");
+        if (Boolean.TRUE.equals(match)) {
+            assertEquals(0, baos.toByteArray().length);
+            verify(resp).sendError(HttpServletResponse.SC_NOT_MODIFIED);
+        } else {
+            assertEquals(s, baos.toString());
+            verify(resp).setHeader("ETag", getETag(digest));
+        }
+    }
+
+    private String getETag(String digest) {
+        return digest;
+    }
 }