diff --git a/openbis_api/source/java/ch/systemsx/cisd/openbis/generic/shared/api/v1/dto/ExperimentIdentifier.java b/openbis_api/source/java/ch/systemsx/cisd/openbis/generic/shared/api/v1/dto/ExperimentIdentifier.java
index bc279e14d8ac480e4189be1363ca13210c6e0cc0..cd52530da7f43bd4ffe6b4e0f9d4921b3b167057 100644
--- a/openbis_api/source/java/ch/systemsx/cisd/openbis/generic/shared/api/v1/dto/ExperimentIdentifier.java
+++ b/openbis_api/source/java/ch/systemsx/cisd/openbis/generic/shared/api/v1/dto/ExperimentIdentifier.java
@@ -16,6 +16,8 @@
 
 package ch.systemsx.cisd.openbis.generic.shared.api.v1.dto;
 
+import java.io.Serializable;
+
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang.builder.EqualsBuilder;
 import org.apache.commons.lang.builder.HashCodeBuilder;
@@ -34,7 +36,7 @@ import ch.systemsx.cisd.common.reflection.ModifiedShortPrefixToStringStyle;
  */
 @SuppressWarnings("unused")
 @JsonObject("ExperimentIdentifier")
-public class ExperimentIdentifier implements IPermanentIdentifier, IDatabaseIdentifier
+public class ExperimentIdentifier implements Serializable, IPermanentIdentifier, IDatabaseIdentifier
 {
     private static final long serialVersionUID = 1L;
 
diff --git a/openbis_api/source/java/ch/systemsx/cisd/openbis/generic/shared/api/v1/dto/ProjectIdentifier.java b/openbis_api/source/java/ch/systemsx/cisd/openbis/generic/shared/api/v1/dto/ProjectIdentifier.java
index ca2f4c70c4d037dcf88ba7913512f275c7649d7a..8ac113ce45c77afd92dc6ead0f5823f5ead7e196 100644
--- a/openbis_api/source/java/ch/systemsx/cisd/openbis/generic/shared/api/v1/dto/ProjectIdentifier.java
+++ b/openbis_api/source/java/ch/systemsx/cisd/openbis/generic/shared/api/v1/dto/ProjectIdentifier.java
@@ -16,6 +16,8 @@
 
 package ch.systemsx.cisd.openbis.generic.shared.api.v1.dto;
 
+import java.io.Serializable;
+
 import org.apache.commons.lang.builder.EqualsBuilder;
 import org.apache.commons.lang.builder.HashCodeBuilder;
 import org.apache.commons.lang.builder.ToStringBuilder;
@@ -33,7 +35,7 @@ import ch.systemsx.cisd.common.reflection.ModifiedShortPrefixToStringStyle;
  */
 @SuppressWarnings("unused")
 @JsonObject("ProjectIdentifier")
-public class ProjectIdentifier implements IPermanentIdentifier, IDatabaseIdentifier
+public class ProjectIdentifier implements Serializable, IPermanentIdentifier, IDatabaseIdentifier
 {
     private static final long serialVersionUID = 1L;
 
diff --git a/openbis_api/source/java/ch/systemsx/cisd/openbis/generic/shared/api/v1/dto/SampleIdentifier.java b/openbis_api/source/java/ch/systemsx/cisd/openbis/generic/shared/api/v1/dto/SampleIdentifier.java
index 6a0cf8da1ce4dbf979de5bd3d703110175e541c5..4b2216f15f2394db5cd9d31ac9dec09bbe5c5fc1 100644
--- a/openbis_api/source/java/ch/systemsx/cisd/openbis/generic/shared/api/v1/dto/SampleIdentifier.java
+++ b/openbis_api/source/java/ch/systemsx/cisd/openbis/generic/shared/api/v1/dto/SampleIdentifier.java
@@ -16,6 +16,8 @@
 
 package ch.systemsx.cisd.openbis.generic.shared.api.v1.dto;
 
+import java.io.Serializable;
+
 import org.apache.commons.lang.builder.EqualsBuilder;
 import org.apache.commons.lang.builder.HashCodeBuilder;
 import org.apache.commons.lang.builder.ToStringBuilder;
@@ -33,7 +35,7 @@ import ch.systemsx.cisd.common.reflection.ModifiedShortPrefixToStringStyle;
  */
 @SuppressWarnings("unused")
 @JsonObject("SampleIdentifier")
-public class SampleIdentifier implements IPermanentIdentifier, IDatabaseIdentifier
+public class SampleIdentifier implements Serializable, IPermanentIdentifier, IDatabaseIdentifier
 {
     private static final long serialVersionUID = 1L;