diff --git a/core-domain/src/main/java/org/uniprot/core/proteome/impl/ProteomeStatisticsImpl.java b/core-domain/src/main/java/org/uniprot/core/proteome/impl/ProteomeStatisticsImpl.java
index 3f425e4b1..7af954e5d 100644
--- a/core-domain/src/main/java/org/uniprot/core/proteome/impl/ProteomeStatisticsImpl.java
+++ b/core-domain/src/main/java/org/uniprot/core/proteome/impl/ProteomeStatisticsImpl.java
@@ -1,11 +1,12 @@
 package org.uniprot.core.proteome.impl;
 
-import java.util.Objects;
-
 import org.uniprot.core.impl.StatisticsImpl;
 import org.uniprot.core.proteome.ProteomeStatistics;
 
+import java.util.Objects;
+
 public class ProteomeStatisticsImpl extends StatisticsImpl implements ProteomeStatistics {
+    private static final long serialVersionUID = -8585233468042758658L;
     private final long isoformProteinCount;
 
     ProteomeStatisticsImpl(
@@ -14,6 +15,10 @@ public class ProteomeStatisticsImpl extends StatisticsImpl implements ProteomeSt
         this.isoformProteinCount = isoformProteinCount;
     }
 
+    ProteomeStatisticsImpl() {
+        this(0, 0,0);
+    }
+
     @Override
     public long getIsoformProteinCount() {
         return isoformProteinCount;
diff --git a/core-domain/src/test/java/org/uniprot/core/proteome/impl/ProteomeStatisticsImplTest.java b/core-domain/src/test/java/org/uniprot/core/proteome/impl/ProteomeStatisticsImplTest.java
index e4e27baf5..e1e3edcae 100644
--- a/core-domain/src/test/java/org/uniprot/core/proteome/impl/ProteomeStatisticsImplTest.java
+++ b/core-domain/src/test/java/org/uniprot/core/proteome/impl/ProteomeStatisticsImplTest.java
@@ -1,9 +1,10 @@
 package org.uniprot.core.proteome.impl;
 
-import static org.junit.jupiter.api.Assertions.*;
-
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+
 class ProteomeStatisticsImplTest {
     public static final int REVIEWED_PROTEIN_COUNT = 98;
     public static final int UNREVIEWED_PROTEIN_COUNT = 33;
@@ -20,6 +21,13 @@ void getCountsAreAccurate() {
         assertEquals(ISOFORM_PROTEIN_COUNT, PROTEOME_STATISTICS.getIsoformProteinCount());
     }
 
+    @Test
+    void defaultConstructor() {
+        ProteomeStatisticsImpl that =
+                new ProteomeStatisticsImpl();
+        assertEquals(new ProteomeStatisticsImpl(0, 0, 0), that);
+    }
+
     @Test
     void equals_whenTrue() {
         ProteomeStatisticsImpl that =
diff --git a/json-parser/src/main/java/org/uniprot/core/json/parser/proteome/ProteomeJsonConfig.java b/json-parser/src/main/java/org/uniprot/core/json/parser/proteome/ProteomeJsonConfig.java
index 9040fee57..20b2115e8 100644
--- a/json-parser/src/main/java/org/uniprot/core/json/parser/proteome/ProteomeJsonConfig.java
+++ b/json-parser/src/main/java/org/uniprot/core/json/parser/proteome/ProteomeJsonConfig.java
@@ -1,41 +1,19 @@
 package org.uniprot.core.json.parser.proteome;
 
-import java.time.LocalDate;
-
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.jsontype.NamedType;
+import com.fasterxml.jackson.databind.module.SimpleModule;
 import org.uniprot.core.CrossReference;
 import org.uniprot.core.Database;
 import org.uniprot.core.Value;
-import org.uniprot.core.citation.Author;
-import org.uniprot.core.citation.Book;
-import org.uniprot.core.citation.ElectronicArticle;
-import org.uniprot.core.citation.Journal;
-import org.uniprot.core.citation.JournalArticle;
-import org.uniprot.core.citation.Locator;
-import org.uniprot.core.citation.Patent;
-import org.uniprot.core.citation.PublicationDate;
-import org.uniprot.core.citation.Submission;
-import org.uniprot.core.citation.Thesis;
-import org.uniprot.core.citation.Unpublished;
-import org.uniprot.core.citation.impl.AuthorImpl;
-import org.uniprot.core.citation.impl.BookImpl;
-import org.uniprot.core.citation.impl.ElectronicArticleImpl;
-import org.uniprot.core.citation.impl.JournalArticleImpl;
-import org.uniprot.core.citation.impl.JournalImpl;
-import org.uniprot.core.citation.impl.PatentImpl;
-import org.uniprot.core.citation.impl.PublicationDateImpl;
-import org.uniprot.core.citation.impl.SubmissionImpl;
-import org.uniprot.core.citation.impl.ThesisImpl;
-import org.uniprot.core.citation.impl.UnpublishedImpl;
+import org.uniprot.core.citation.*;
+import org.uniprot.core.citation.impl.*;
 import org.uniprot.core.impl.CrossReferenceImpl;
 import org.uniprot.core.impl.DefaultDatabase;
 import org.uniprot.core.impl.ValueImpl;
 import org.uniprot.core.json.parser.JsonConfig;
 import org.uniprot.core.json.parser.deserializer.LocalDateDeserializer;
-import org.uniprot.core.json.parser.serializer.AuthorSerializer;
-import org.uniprot.core.json.parser.serializer.JournalSerializer;
-import org.uniprot.core.json.parser.serializer.LocalDateSerializer;
-import org.uniprot.core.json.parser.serializer.LocatorSerializer;
-import org.uniprot.core.json.parser.serializer.PublicationDateSerializer;
+import org.uniprot.core.json.parser.serializer.*;
 import org.uniprot.core.json.parser.uniprot.serializer.UniProtKBAccessionSerializer;
 import org.uniprot.core.proteome.*;
 import org.uniprot.core.proteome.impl.*;
@@ -46,9 +24,7 @@
 import org.uniprot.core.uniprotkb.taxonomy.Taxonomy;
 import org.uniprot.core.uniprotkb.taxonomy.impl.TaxonomyImpl;
 
-import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.jsontype.NamedType;
-import com.fasterxml.jackson.databind.module.SimpleModule;
+import java.time.LocalDate;
 
 public class ProteomeJsonConfig extends JsonConfig {
     private static ProteomeJsonConfig instance;
@@ -89,6 +65,7 @@ private ObjectMapper initObjectMapper() {
         mod.addAbstractTypeMapping(ProteomeId.class, ProteomeIdImpl.class);
         mod.addAbstractTypeMapping(Taxonomy.class, TaxonomyImpl.class);
         mod.addAbstractTypeMapping(TaxonomyLineage.class, TaxonomyLineageImpl.class);
+        mod.addAbstractTypeMapping(ProteomeStatistics.class, ProteomeStatisticsImpl.class);
 
         mod.addAbstractTypeMapping(Value.class, ValueImpl.class);
         mod.addAbstractTypeMapping(RedundantProteome.class, RedundantProteomeImpl.class);