diff --git a/core/src/main/java/hudson/PluginManager.java b/core/src/main/java/hudson/PluginManager.java
index 75be36bb73..41580095c1 100644
--- a/core/src/main/java/hudson/PluginManager.java
+++ b/core/src/main/java/hudson/PluginManager.java
@@ -196,7 +196,7 @@ public abstract class PluginManager extends AbstractModelObject {
                                             PluginWrapper p = strategy.createPluginWrapper(arc);
                                             if (isDuplicate(p)) return;
 
-                                            p.isBundled = bundledPlugins.contains(arc.getName());
+                                            p.isBundled = containsHpiJpi(bundledPlugins, arc.getName());
                                             plugins.add(p);
                                         } catch (IOException e) {
                                             failedPlugins.add(new FailedPlugin(arc.getName(),e));
@@ -344,6 +344,15 @@ public abstract class PluginManager extends AbstractModelObject {
         }});
     }
 
+    /*
+     * contains operation that considers xxx.hpi and xxx.jpi as equal
+     * this is necessary since the bundled plugins are still called *.hpi 
+     */
+    private boolean containsHpiJpi(Collection<String> bundledPlugins, String name) {
+        return bundledPlugins.contains(name.replaceAll("\\.hpi",".jpi"))
+                || bundledPlugins.contains(name.replaceAll("\\.jpi",".hpi"));
+    }
+
     /**
      * TODO: revisit where/how to expose this. This is an experiment.
      */
diff --git a/test/src/test/java/hudson/PluginManagerTest2.java b/test/src/test/java/hudson/PluginManagerTest2.java
new file mode 100644
index 0000000000..fc1fbbf976
--- /dev/null
+++ b/test/src/test/java/hudson/PluginManagerTest2.java
@@ -0,0 +1,64 @@
+package hudson;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+
+import javax.servlet.ServletContext;
+
+import org.jvnet.hudson.test.HudsonTestCase;
+import org.jvnet.hudson.test.recipes.WithPlugin;
+import org.xml.sax.SAXException;
+
+import com.gargoylesoftware.htmlunit.html.HtmlForm;
+import com.gargoylesoftware.htmlunit.html.HtmlPage;
+import org.apache.commons.io.FileUtils;
+
+public class PluginManagerTest2 extends HudsonTestCase {
+    @Override
+    protected void setUp() throws Exception {
+        setPluginManager(null); // use a fresh instance
+        super.setUp();
+    }
+
+    private ServletContext servletContext;
+
+    // need to keep the ServletContext to use in the actual test
+    protected ServletContext createWebServer() throws Exception {
+        servletContext=super.createWebServer();
+        return servletContext;
+    }
+
+    @WithPlugin("tasks.jpi")
+    public void testPinned() throws Exception {
+        PluginWrapper tasks = hudson.getPluginManager().getPlugin("tasks");
+        assertFalse("tasks shouldn't be bundled",tasks.isBundled());
+        assertFalse("tasks shouldn't be pinned before update",tasks.isPinned());
+        uploadPlugin("tasks.jpi", false);
+        assertFalse("tasks shouldn't be pinned after update",tasks.isPinned());
+
+        PluginWrapper cvs = hudson.getPluginManager().getPlugin("cvs");
+        assertTrue("cvs should be bundled",cvs.isBundled());
+        assertFalse("cvs shouldn't be pinned before update",cvs.isPinned());
+        uploadPlugin("cvs.hpi", true);
+        assertTrue("cvs should be pinned after update",cvs.isPinned());
+    }
+
+    private void uploadPlugin(String pluginName, boolean useServerRoot) throws IOException, SAXException, Exception {
+        HtmlPage page = new WebClient().goTo("pluginManager/advanced");
+        HtmlForm f = page.getFormByName("uploadPlugin");
+        File plugin;
+        if(useServerRoot) {
+            String pluginsPath=servletContext.getRealPath("WEB-INF/plugins");
+            plugin = new File(pluginsPath+"/"+pluginName);
+       } else {
+            File dir = env.temporaryDirectoryAllocator.allocate();
+            plugin = new File(dir, pluginName);
+            URL resource = getClass().getClassLoader().getResource("plugins/"+pluginName);
+            FileUtils.copyURLToFile(resource,plugin);
+        }
+        f.getInputByName("name").setValueAttribute(plugin.getAbsolutePath());
+        submit(f);
+    }
+
+}