diff --git a/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/GraphCleaningFunctions.java b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/GraphCleaningFunctions.java
index 6cb0b7218..b4a666b81 100644
--- a/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/GraphCleaningFunctions.java
+++ b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/GraphCleaningFunctions.java
@@ -119,7 +119,7 @@ public class GraphCleaningFunctions extends CleaningFunctions {
 							.getContext()
 							.stream()
 							.filter(c -> !StringUtils.startsWith(c.getId().toLowerCase(), contextId))
-							.collect(Collectors.toList()));
+							.collect(Collectors.toCollection(ArrayList::new)));
 			}
 			return (T) res;
 		} else {
diff --git a/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/MergeUtils.java b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/MergeUtils.java
index f1221add3..ac51705d2 100644
--- a/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/MergeUtils.java
+++ b/dhp-common/src/main/java/eu/dnetlib/dhp/schema/oaf/utils/MergeUtils.java
@@ -432,7 +432,10 @@ public class MergeUtils {
 
 		// merge datainfo for same context id
 		merge.setContext(mergeLists(merge.getContext(), enrich.getContext(), trust, Context::getId, (r, l) -> {
-			r.getDataInfo().addAll(l.getDataInfo());
+			ArrayList<DataInfo> di = new ArrayList<>();
+			di.addAll(r.getDataInfo());
+			di.addAll(l.getDataInfo());
+			r.setDataInfo(di);
 			return r;
 		}));