diff --git a/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/common/fetchoptions/FetchOptions.java b/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/common/fetchoptions/FetchOptions.java
index f8b905138d201b6e891440ee2893772c366c09ee..0f740ad00138ad9c83b8d10fc0048f08408e7c60 100644
--- a/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/common/fetchoptions/FetchOptions.java
+++ b/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/common/fetchoptions/FetchOptions.java
@@ -58,6 +58,7 @@ public abstract class FetchOptions<OBJECT> implements Serializable
 
     public abstract SortOptions<OBJECT> getSortBy();
 
+    @JsonIgnore
     public FetchOptionsToStringBuilder getFetchOptionsStringBuilder()
     {
         FetchOptionsToStringBuilder f = new FetchOptionsToStringBuilder("?", this);
diff --git a/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/vocabulary/fetchoptions/VocabularyTermFetchOptions.java b/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/vocabulary/fetchoptions/VocabularyTermFetchOptions.java
index 50025da13f301af11eff1e8d562337bae07c453c..3065ba72723dc715b23073316851e579c0cb37bd 100644
--- a/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/vocabulary/fetchoptions/VocabularyTermFetchOptions.java
+++ b/openbis_api/source/java/ch/ethz/sis/openbis/generic/asapi/v3/dto/vocabulary/fetchoptions/VocabularyTermFetchOptions.java
@@ -17,6 +17,7 @@ package ch.ethz.sis.openbis.generic.asapi.v3.dto.vocabulary.fetchoptions;
 
 import java.io.Serializable;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 import ch.ethz.sis.openbis.generic.asapi.v3.dto.common.fetchoptions.FetchOptions;
@@ -103,6 +104,8 @@ public class VocabularyTermFetchOptions extends FetchOptions<VocabularyTerm> imp
     {
         return sort;
     }
+    
+    @JsonIgnore
     @Override
     public FetchOptionsToStringBuilder getFetchOptionsStringBuilder()
     {