diff --git a/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/ODataJsonSerializer.java b/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/ODataJsonSerializer.java
index edca2e436..3d6aa6898 100644
--- a/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/ODataJsonSerializer.java
+++ b/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/ODataJsonSerializer.java
@@ -311,13 +311,6 @@ public class ODataJsonSerializer extends AbstractODataSerializer {
     return true;
   }
 
-  private boolean cycleDetected(final Set<String> ancestors, String child) {
-      if (ancestors == null) {
-          return false;
-      }
-      return ancestors.contains(child);
-  }
-  
   protected void writeEntity(final ServiceMetadata metadata, final EdmEntityType entityType, final Entity entity,
       final ContextURL contextURL, final ExpandOption expand, Integer toDepth, 
       final SelectOption select, final boolean onlyReference, Set<String> ancestors, final JsonGenerator json)
diff --git a/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/xml/ODataXmlSerializer.java b/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/xml/ODataXmlSerializer.java
index d8acbf451..06bb13d52 100644
--- a/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/xml/ODataXmlSerializer.java
+++ b/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/xml/ODataXmlSerializer.java
@@ -427,13 +427,6 @@ public class ODataXmlSerializer extends AbstractODataSerializer {
     return entity.getId().toASCIIString();
   }  
 
-  private boolean cycleDetected(final Set<String> ancestors, String child) {
-      if (ancestors == null) {
-          return false;
-      }
-      return ancestors.contains(child);
-  }
-  
   protected void writeEntity(final ServiceMetadata metadata, final EdmEntityType entityType,
       final Entity entity, final ContextURL contextURL, final ExpandOption expand, final Integer toDepth,
       final SelectOption select, final String xml10InvalidCharReplacement,