diff --git a/src/main/java/org/gcube/datacatalogue/ckanutillibrary/DataCatalogueImpl.java b/src/main/java/org/gcube/datacatalogue/ckanutillibrary/DataCatalogueImpl.java
index 561d921..b489fa5 100644
--- a/src/main/java/org/gcube/datacatalogue/ckanutillibrary/DataCatalogueImpl.java
+++ b/src/main/java/org/gcube/datacatalogue/ckanutillibrary/DataCatalogueImpl.java
@@ -1931,6 +1931,9 @@ public class DataCatalogueImpl implements DataCatalogue{
 		Map<String, List<String>> fromCKANCustomFields = new HashMap<String, List<String>>();
 		CheckedCkanClient client = new CheckedCkanClient(CKAN_CATALOGUE_URL, apiKey);
 		List<CkanPair> extras = client.getDataset(productId).getExtras();
+		
+		if(extras == null)
+			extras = new ArrayList<CkanPair>();
 
 		// fill the above map with these values
 		for (CkanPair ckanPair : extras) {