diff --git a/scm-webapp/src/main/java/sonia/scm/filter/TypedWebElementDescriptor.java b/scm-webapp/src/main/java/sonia/scm/filter/TypedWebElementDescriptor.java
index 4a69c7540c..c3ef626f5c 100644
--- a/scm-webapp/src/main/java/sonia/scm/filter/TypedWebElementDescriptor.java
+++ b/scm-webapp/src/main/java/sonia/scm/filter/TypedWebElementDescriptor.java
@@ -21,11 +21,10 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.filter;
 
-import java.util.Objects;
-
+import lombok.Value;
 import sonia.scm.plugin.WebElementDescriptor;
 
 /**
@@ -34,48 +33,8 @@ import sonia.scm.plugin.WebElementDescriptor;
  * @param <T>
  * @since 2.0.0
  */
-public final class TypedWebElementDescriptor<T> 
-{
-  private final Class<T> clazz;
-  private final WebElementDescriptor descriptor;
-
-  public TypedWebElementDescriptor(Class<T> clazz,
-    WebElementDescriptor descriptor)
-  {
-    this.clazz = clazz;
-    this.descriptor = descriptor;
-  }
-
-  public Class<T> getClazz()
-  {
-    return clazz;
-  }
-
-  public WebElementDescriptor getDescriptor()
-  {
-    return descriptor;
-  }
-  
-  @Override
-  public int hashCode() {
-    return Objects.hash(clazz, descriptor);
-  }
-
-  @Override
-  public boolean equals(Object obj) {
-    if (this == obj) {
-      return true;
-    }
-    if (obj == null) {
-      return false;
-    }
-    if (getClass() != obj.getClass()) {
-      return false;
-    }
-    
-    final TypedWebElementDescriptor other = (TypedWebElementDescriptor) obj;
-    return Objects.equals(clazz, other.clazz)
-      && Objects.equals(descriptor, other.descriptor);
-  }
-  
+@Value
+public class TypedWebElementDescriptor<T> {
+  Class<T> clazz;
+  WebElementDescriptor descriptor;
 }
diff --git a/scm-webapp/src/main/java/sonia/scm/filter/WebElementCollector.java b/scm-webapp/src/main/java/sonia/scm/filter/WebElementCollector.java
index da073deefa..d37a2e90c5 100644
--- a/scm-webapp/src/main/java/sonia/scm/filter/WebElementCollector.java
+++ b/scm-webapp/src/main/java/sonia/scm/filter/WebElementCollector.java
@@ -69,9 +69,8 @@ public final class WebElementCollector
   @SuppressWarnings("unchecked")
   private WebElementCollector(Iterable<WebElementExtension> elements)
   {
-    List<TypedWebElementDescriptor<? extends Filter>> fl = Lists.newArrayList();
-    List<TypedWebElementDescriptor<? extends HttpServlet>> sl =
-      Lists.newArrayList();
+    List<TypedWebElementDescriptor<Filter>> fl = Lists.newArrayList();
+    List<TypedWebElementDescriptor<HttpServlet>> sl = Lists.newArrayList();
 
     for (WebElementExtension element : elements)
     {
@@ -79,13 +78,13 @@ public final class WebElementCollector
       {
         fl.add(
           new TypedWebElementDescriptor<>(
-            (Class<? extends Filter>) element.getClazz(), element.getDescriptor()));
+            (Class<Filter>) element.getClazz(), element.getDescriptor()));
       }
       else if (Servlet.class.isAssignableFrom(element.getClazz()))
       {
         sl.add(
           new TypedWebElementDescriptor<>(
-            (Class<? extends HttpServlet>) element.getClazz(), element.getDescriptor()));
+            (Class<HttpServlet>) element.getClazz(), element.getDescriptor()));
       }
       else
       {
@@ -95,8 +94,7 @@ public final class WebElementCollector
       }
     }
 
-    TypedWebElementDescriptorOrdering ordering =
-      new TypedWebElementDescriptorOrdering();
+    TypedWebElementDescriptorOrdering ordering = new TypedWebElementDescriptorOrdering();
 
     filters = ordering.immutableSortedCopy(fl);
     servlets = ordering.immutableSortedCopy(sl);
@@ -126,7 +124,7 @@ public final class WebElementCollector
    *
    * @return
    */
-  public Iterable<TypedWebElementDescriptor<? extends Filter>> getFilters()
+  public Iterable<TypedWebElementDescriptor<Filter>> getFilters()
   {
     return filters;
   }
@@ -137,7 +135,7 @@ public final class WebElementCollector
    *
    * @return
    */
-  public Iterable<TypedWebElementDescriptor<? extends HttpServlet>> getServlets()
+  public Iterable<TypedWebElementDescriptor<HttpServlet>> getServlets()
   {
     return servlets;
   }
@@ -177,8 +175,8 @@ public final class WebElementCollector
   //~--- fields ---------------------------------------------------------------
 
   /** Field description */
-  private final Iterable<TypedWebElementDescriptor<? extends Filter>> filters;
+  private final Iterable<TypedWebElementDescriptor<Filter>> filters;
 
   /** Field description */
-  private final Iterable<TypedWebElementDescriptor<? extends HttpServlet>> servlets;
+  private final Iterable<TypedWebElementDescriptor<HttpServlet>> servlets;
 }
diff --git a/scm-webapp/src/main/java/sonia/scm/filter/WebElementModule.java b/scm-webapp/src/main/java/sonia/scm/filter/WebElementModule.java
index 482deb063b..9b19b9a7f5 100644
--- a/scm-webapp/src/main/java/sonia/scm/filter/WebElementModule.java
+++ b/scm-webapp/src/main/java/sonia/scm/filter/WebElementModule.java
@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.filter;
 
 //~--- non-JDK imports --------------------------------------------------------
@@ -75,13 +75,12 @@ public class WebElementModule extends ServletModule
   @Override
   protected void configureServlets()
   {
-    for (TypedWebElementDescriptor<? extends Filter> f : collector.getFilters())
+    for (TypedWebElementDescriptor<Filter> f : collector.getFilters())
     {
       bindFilter(f);
     }
 
-    for (TypedWebElementDescriptor<? extends HttpServlet> s :
-      collector.getServlets())
+    for (TypedWebElementDescriptor<HttpServlet> s : collector.getServlets())
     {
       bindServlet(s);
     }
@@ -93,9 +92,9 @@ public class WebElementModule extends ServletModule
    *
    * @param filter
    */
-  private void bindFilter(TypedWebElementDescriptor<? extends Filter> filter)
+  private void bindFilter(TypedWebElementDescriptor<Filter> filter)
   {
-    Class<? extends Filter> clazz = filter.getClazz();
+    Class<Filter> clazz = filter.getClazz();
 
     logger.info("bind filter {} to filter chain", clazz);
 
@@ -125,9 +124,9 @@ public class WebElementModule extends ServletModule
    * @param servlet
    */
   private void bindServlet(
-    TypedWebElementDescriptor<? extends HttpServlet> servlet)
+    TypedWebElementDescriptor<HttpServlet> servlet)
   {
-    Class<? extends HttpServlet> clazz = servlet.getClazz();
+    Class<HttpServlet> clazz = servlet.getClazz();
 
     logger.info("bind servlet {} to servlet chain", clazz);
 
diff --git a/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginLoader.java b/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginLoader.java
index 77f6b392b9..90f349a3b1 100644
--- a/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginLoader.java
+++ b/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginLoader.java
@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-    
+
 package sonia.scm.plugin;
 
 //~--- non-JDK imports --------------------------------------------------------
@@ -29,25 +29,17 @@ package sonia.scm.plugin;
 import com.google.common.base.Throwables;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.ImmutableSet.Builder;
-import com.google.common.collect.Iterables;
-
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-//~--- JDK imports ------------------------------------------------------------
 
+import javax.servlet.ServletContext;
+import javax.xml.bind.JAXBContext;
+import javax.xml.bind.JAXBException;
 import java.io.IOException;
-
 import java.net.URL;
-
 import java.util.Collection;
 import java.util.Enumeration;
 import java.util.Set;
 
-import javax.servlet.ServletContext;
-
-import javax.xml.bind.JAXBContext;
-import javax.xml.bind.JAXBException;
+//~--- JDK imports ------------------------------------------------------------
 
 /**
  *
@@ -62,10 +54,6 @@ public class DefaultPluginLoader implements PluginLoader
   /** Field description */
   public static final String PATH_PLUGINCONFIG = "META-INF/scm/plugin.xml";
 
-  /** the logger for DefaultPluginLoader */
-  private static final Logger logger =
-    LoggerFactory.getLogger(DefaultPluginLoader.class);
-
   //~--- constructors ---------------------------------------------------------
 
   /**
@@ -90,7 +78,7 @@ public class DefaultPluginLoader implements PluginLoader
 
       modules = getInstalled(parent, context, PATH_MODULECONFIG);
 
-      collector = new ExtensionCollector(parent, modules, installedPlugins);
+      ExtensionCollector collector = new ExtensionCollector(parent, modules, installedPlugins);
       extensionProcessor = new DefaultExtensionProcessor(collector);
     }
     catch (IOException | JAXBException ex)
@@ -198,9 +186,6 @@ public class DefaultPluginLoader implements PluginLoader
 
   //~--- fields ---------------------------------------------------------------
 
-  /** Field description */
-  private final ExtensionCollector collector;
-
   /** Field description */
   private final ExtensionProcessor extensionProcessor;
 
diff --git a/scm-webapp/src/main/java/sonia/scm/plugin/ExtensionCollector.java b/scm-webapp/src/main/java/sonia/scm/plugin/ExtensionCollector.java
index dadb7618a3..2d2b11ebdb 100644
--- a/scm-webapp/src/main/java/sonia/scm/plugin/ExtensionCollector.java
+++ b/scm-webapp/src/main/java/sonia/scm/plugin/ExtensionCollector.java
@@ -98,7 +98,7 @@ public final class ExtensionCollector
 
     if (collection == null)
     {
-      collection = Collections.EMPTY_SET;
+      collection = Collections.emptySet();
     }
 
     return collection;
@@ -123,7 +123,7 @@ public final class ExtensionCollector
     }
     else
     {
-      exts = Collections.EMPTY_SET;
+      exts = Collections.emptySet();
     }
 
     return exts;