diff --git a/dhp-workflows/dhp-rdfconverter/src/main/java/eu/dnetlib/dhp/rdfconverter/utils/RDFConverter.java b/dhp-workflows/dhp-rdfconverter/src/main/java/eu/dnetlib/dhp/rdfconverter/utils/RDFConverter.java
index 3822648a3..7908b481e 100644
--- a/dhp-workflows/dhp-rdfconverter/src/main/java/eu/dnetlib/dhp/rdfconverter/utils/RDFConverter.java
+++ b/dhp-workflows/dhp-rdfconverter/src/main/java/eu/dnetlib/dhp/rdfconverter/utils/RDFConverter.java
@@ -254,6 +254,18 @@ public class RDFConverter {
 					});
 			});
 
+		dataciteProteins
+			.stream()
+			.filter(d -> (d.getSubjects() != null && !d.getSubjects().isEmpty()))
+			.forEach(d -> {
+				Map<String, DataciteProtein.Subject> cleanedSubjects = new HashMap<>();
+				d.getSubjects().stream().forEach(s -> {
+					cleanedSubjects.putIfAbsent(s.getValue(), s);
+				});
+				d.getSubjects().clear();
+				d.setSubjects(cleanedSubjects.values().stream().collect(Collectors.toList()));
+			});
+
 		dataciteProteins.forEach(d -> {
 			DataciteProtein.Title title = new DataciteProtein.Title();
 			title.setTitle(d.getId() + " - ".concat(mainTitles.get(0)));