diff --git a/scm-core/src/main/java/sonia/scm/AlreadyExistsException.java b/scm-core/src/main/java/sonia/scm/AlreadyExistsException.java
index 17863c364c..3ca8335346 100644
--- a/scm-core/src/main/java/sonia/scm/AlreadyExistsException.java
+++ b/scm-core/src/main/java/sonia/scm/AlreadyExistsException.java
@@ -3,15 +3,12 @@ package sonia.scm;
 import java.util.List;
 
 import static java.util.Collections.singletonList;
-import static java.util.Collections.unmodifiableList;
 import static java.util.stream.Collectors.joining;
 
-public class AlreadyExistsException extends RuntimeException implements ExceptionWithContext {
+public class AlreadyExistsException extends ExceptionWithContext {
 
   private static final String CODE = "FtR7UznKU1";
 
-  private final List<ContextEntry> context;
-
   public AlreadyExistsException(ModelObject object) {
     this(singletonList(new ContextEntry(object.getClass(), object.getId())));
   }
@@ -21,12 +18,7 @@ public class AlreadyExistsException extends RuntimeException implements Exceptio
   }
 
   private AlreadyExistsException(List<ContextEntry> context) {
-    super(createMessage(context));
-    this.context = context;
-  }
-
-  public List<ContextEntry> getContext() {
-    return unmodifiableList(context);
+    super(context, createMessage(context));
   }
 
   @Override
diff --git a/scm-core/src/main/java/sonia/scm/ConcurrentModificationException.java b/scm-core/src/main/java/sonia/scm/ConcurrentModificationException.java
index 6fb8ac2b62..d566859b4c 100644
--- a/scm-core/src/main/java/sonia/scm/ConcurrentModificationException.java
+++ b/scm-core/src/main/java/sonia/scm/ConcurrentModificationException.java
@@ -3,15 +3,12 @@ package sonia.scm;
 import java.util.Collections;
 import java.util.List;
 
-import static java.util.Collections.unmodifiableList;
 import static java.util.stream.Collectors.joining;
 
-public class ConcurrentModificationException extends RuntimeException implements ExceptionWithContext {
+public class ConcurrentModificationException extends ExceptionWithContext {
 
   private static final String CODE = "2wR7UzpPG1";
 
-  private final List<ContextEntry> context;
-
   public ConcurrentModificationException(Class type, String id) {
     this(Collections.singletonList(new ContextEntry(type, id)));
   }
@@ -21,12 +18,7 @@ public class ConcurrentModificationException extends RuntimeException implements
   }
 
   private ConcurrentModificationException(List<ContextEntry> context) {
-    super(createMessage(context));
-    this.context = context;
-  }
-
-  public List<ContextEntry> getContext() {
-    return unmodifiableList(context);
+    super(context, createMessage(context));
   }
 
   @Override
diff --git a/scm-core/src/main/java/sonia/scm/ExceptionWithContext.java b/scm-core/src/main/java/sonia/scm/ExceptionWithContext.java
index 93edc1f63b..255738455c 100644
--- a/scm-core/src/main/java/sonia/scm/ExceptionWithContext.java
+++ b/scm-core/src/main/java/sonia/scm/ExceptionWithContext.java
@@ -2,10 +2,20 @@ package sonia.scm;
 
 import java.util.List;
 
-public interface ExceptionWithContext {
-  List<ContextEntry> getContext();
+import static java.util.Collections.unmodifiableList;
 
-  String getMessage();
+public abstract class ExceptionWithContext extends RuntimeException {
 
-  String getCode();
+  private final List<ContextEntry> context;
+
+  public ExceptionWithContext(List<ContextEntry> context, String message) {
+    super(message);
+    this.context = context;
+  }
+
+  public List<ContextEntry> getContext() {
+    return unmodifiableList(context);
+  }
+
+  public abstract String getCode();
 }
diff --git a/scm-core/src/main/java/sonia/scm/NotFoundException.java b/scm-core/src/main/java/sonia/scm/NotFoundException.java
index 30696c73b6..69b9617e93 100644
--- a/scm-core/src/main/java/sonia/scm/NotFoundException.java
+++ b/scm-core/src/main/java/sonia/scm/NotFoundException.java
@@ -1,21 +1,14 @@
 package sonia.scm;
 
-import sonia.scm.repository.NamespaceAndName;
-import sonia.scm.repository.Repository;
-
 import java.util.Collections;
-import java.util.LinkedList;
 import java.util.List;
 
-import static java.util.Collections.unmodifiableList;
 import static java.util.stream.Collectors.joining;
 
-public class NotFoundException extends RuntimeException implements ExceptionWithContext {
+public class NotFoundException extends ExceptionWithContext {
 
   private static final String CODE = "AGR7UzkhA1";
 
-  private final List<ContextEntry> context;
-
   public NotFoundException(Class type, String id) {
     this(Collections.singletonList(new ContextEntry(type, id)));
   }
@@ -29,12 +22,7 @@ public class NotFoundException extends RuntimeException implements ExceptionWith
   }
 
   private NotFoundException(List<ContextEntry> context) {
-    super(createMessage(context));
-    this.context = context;
-  }
-
-  public List<ContextEntry> getContext() {
-    return unmodifiableList(context);
+    super(context, createMessage(context));
   }
 
   @Override
diff --git a/scm-webapp/src/main/java/sonia/scm/api/rest/ContextualExceptionMapper.java b/scm-webapp/src/main/java/sonia/scm/api/rest/ContextualExceptionMapper.java
index b25af05d50..43b8a38ccc 100644
--- a/scm-webapp/src/main/java/sonia/scm/api/rest/ContextualExceptionMapper.java
+++ b/scm-webapp/src/main/java/sonia/scm/api/rest/ContextualExceptionMapper.java
@@ -1,6 +1,5 @@
 package sonia.scm.api.rest;
 
-import com.google.inject.Inject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import sonia.scm.ExceptionWithContext;
@@ -10,7 +9,7 @@ import sonia.scm.web.VndMediaType;
 import javax.ws.rs.core.Response;
 import javax.ws.rs.ext.ExceptionMapper;
 
-public class ContextualExceptionMapper<E extends Throwable & ExceptionWithContext> implements ExceptionMapper<E> {
+public class ContextualExceptionMapper<E extends ExceptionWithContext> implements ExceptionMapper<E> {
 
   private static final Logger logger = LoggerFactory.getLogger(ContextualExceptionMapper.class);